Basic instructions for people who don't already know:

1) Remove the Focus and Zoom rings.

2) Remove the front grill.

3) Remove the lens assembly.

4) Use compressed air to blow out the speck of dusts causing the dust blobs to appear on the screen. (Please be VERY careful of condensation, dripping, and impurities from canned compressed air.)

5) Reassemble everything.


The first 2 pictures show the "before" shot with the dust blobs. The last picture shows the screen after cleaning. The projector is only 8" from screen when I took these pictures (that is why they are out of focus, but the blobs are much easier to see). You can also project onto a piece of paper about 8" away.

http://img257.imageshack.us/img257/9348/img0013medium3ky.jpg

http://img257.imageshack.us/img257/9109/img0014medium3jp.jpg

http://img257.imageshack.us/img257/2884/img0015medium3fw.jpg
I used the tweezers to lasso the string around the focus and zoom rings. Also, a *magnetic* screwdriver is highly recommended. Note: I already have the rings removed in the above picture.

http://img257.imageshack.us/img257/9553/img0016medium0lg.jpg
The small CO2 spray is cleaner, but weak. The can spray is powerful, but may contain impurities. Follow JeffBK's suggestion to test the spray on a mirror first (see post 19 below).

http://img257.imageshack.us/img257/7947/img0017medium5pb.jpg
I came up with the idea to lasso the rings with a string and pull, rather than prying it with a screwdriver and risk scuff marks.

http://img257.imageshack.us/img257/1778/img0018medium1be.jpg
There are 3 locking tabs per ring. Use the lasso to pull one tab at a time. I borrowed D-Train's idea to mark the position of the rings with tape before disassembly.

http://img257.imageshack.us/img257/9369/img0019medium4xs.jpg

http://img257.imageshack.us/img257/6349/img0021medium5rd.jpg

http://img257.imageshack.us/img257/4765/img0022medium9ji.jpg

http://img257.imageshack.us/img257/8033/img0029medium3kx.jpg

http://img257.imageshack.us/img257/2402/img0032medium3na.jpg
The lens with the rings removed. You can now see the 3 screws holding the lens assembly.

http://img257.imageshack.us/img257/2423/img0033medium8mz.jpg
Remove the 2 screws on the underside holding the front grill.

http://img257.imageshack.us/img257/5125/img0034medium9wx.jpg
Shine flashlight through grill to look for the 2 locking tabs (1 on each side), plus 1 more to the right of the lens.

http://img257.imageshack.us/img257/117/img0035medium2oh.jpg
Use small spoon to press down (do not pry) to *easily* release each tab. No need to pry or use force.

http://img257.imageshack.us/img257/6109/img0037medium1uj.jpg

http://img257.imageshack.us/img257/1599/img0038medium4af.jpg
There is no need to remove the light housing. I recommend leaving it in, so that you can run a quick test before final reassembly. However, I recommend removing it if your lamp filter is very dirty.

http://img257.imageshack.us/img257/3078/img0039medium7tb.jpg
Notice the grill deflects the hot exhaust away from the light path.

http://img257.imageshack.us/img257/3230/img0040medium4vv.jpg
Remove the 3 screws holding the lens assembly.

http://img257.imageshack.us/img257/387/img0042medium9mu.jpg
The rainbow colour DMD mirror is now exposed. It is now most vulnerable. CAREFUL not to disturb the dust around you; move slowly, don't breath, don't even blink! If your house is dusty, vacuum and let the air settle before removing the lens assembly. CAUTION: Do NOT use portable vacuums. Fine dust will escape from the filter bag and contaminate the area.

http://img257.imageshack.us/img257/7402/img0043medium6pu.jpg

http://img257.imageshack.us/img257/2318/img0046medium0xu.jpg
Notice the speck of dust on the mirror! Blow it out with compressed air. You will need the straw extension. Also, blow away any dust on the thick lens, and another large mirror opposite to the DMD mirror (not shown). However, I think only dusts on the DMD mirror will cause blobs on the screen. WARNING: Make sure the projector is *completely* cooled (not even slightly warm). Compressed air is cold. Warm glass + cold air = crack!

I suggest testing it again before you snap the grill and rings back on, just in case you missed a spot. CAUTION: If you re-test it, make sure you let a cool down *completely* again before any further cleaning.

http://img257.imageshack.us/img257/601/img0047medium7oo.jpg
This is the lens assembly. It is a sealed unit with rotating zoom and focus. It is greasy. Careful not to get the grease on your fingers or the lens. I recommend washing your hands with soap immediately after removal.

http://img257.imageshack.us/img257/9889/img0048medium7sv.jpg

http://img257.imageshack.us/img257/9559/img0049medium2br.jpg
You can also use this procedure to expose and clean the BACK side of the colour wheel. CAUTION: The colour wheel is VERY fragile. If you press too hard during cleaning, a glass segment may break off. I recommend NOT touching it.

http://img257.imageshack.us/img257/1002/img0053medium8bo.jpg

FINISHED! NO MORE DUST BLOBS!!!

As they say... "A Picture Speaks a Thousand Words". I hope this pictorial guide is self-explanatory. Please feel free to ask me any questions. Special thanks to everybody who has posted before me (JeffKB, D-Train, Cummings66, etc... there were many more) who inspired me to proceed with the procedure and to take these photos in hopes of helping others.

My lasso idea with the string works very well for pulling the focus and zoom rings out. I prefer this method to using a screwdriver to pry out the rings.

Disclaimer: This procedure will void your warranty and may damage your projector. Proceed at your own risk.

Also check out my colour wheel cleaning guide here (http://www.avsforum.com/avs-vb/showthread.php?t=581503).

SuperGoop

SuperGoob,

NICE POST!!

I wish people who has done this to their SP5700 would do the same (post some pics), as I am having dust fibre in the optic and am not game enough to take the thing apart, as I just don't know how it goes together, need a service manual here may be...

Any SP5700 owners?

K

SuperGoop - congratulations on the successful cleaning and the outstanding pictures! I wish I had this thread available to me before I cleaned my dust blobs - it would have been a lot less stressful. :D

Even though there's been a lot of postings describing the procedure, yours is the first that has included detailed photos (at least AFAIK). Between the many detailed written accounts of the cleaning procedure and your pictures, anyone planning on doing the procedure should have an excellent idea of what to expect and what to do.

Nice job. :)

Awsome. Now I hope I never need to use it!

I will be saving this thread for the day I hope never comes... :rolleyes:

Thank-U for taking the time to help out your AVS Brothers & Sisters.

HH

Thanks Goop -- great shots, great service to the 4805 community.

Goop thanks, this will go in my subscribed list for the day I have to clean mine, and you're right a picture is worth a thousand words, hopefully the process won't be as intimidating with these instructions.

Very nice work!! Thank you for putting this together!! I followed JeffKB during his dust removal process, and was hoping for some step by step photos. And now you have put togethr the MOST complete guide to dust removal for the 4805!!

Thanks again!!

Sean

Outstanding Gump!

Nice Job! Hope I NEVER have to come back to this thread for instructions, but nice to know it will be there if I do.

-Redbird

Thanks for the picture tutorial Goop! I have a couple of pictures in my gallery that show just how much of an improvement this procedure can make. You can tell just how much detail is included in your post because there is not a single reply yet that asks for more info.

Would the lasso idea work better with 3 of them at 120 degrees from each other? Just a thought.

Great post, thank you for sharing your work!

Thanks everyone for your positive responses. If anyone tries the procedure, please let us know how it goes. Feel free to add your suggestions to improve the technique.

Would the lasso idea work better with 3 of them at 120 degrees from each other? Just a thought.My short answer is 'no'. I actually thought about that and tried adding another lasso and pulling both at the same time. This created 2 issues:

1) The space was tight to have 2 set of strings together. I doubt 3 sets will fit, especially for the zoom ring. I tried using thinner strings, but they were too weak and snapped easily.

2) It is easier to release 1 tab at a time. The tabs are fairly tight. Pulling one tab is easier than tackling all 3 at the same time. The force will be too great, and I may damage the lens assembly. It is better to pick them off one by one.

Thanks for the suggestion.

Here is an intersting excerpt concerning dust blobs and the Sanyo PLV-Z3 (source: http://www.projectorcentral.com/sanyo_plv-z3.htm):

"One problem that can occur on any projector that does not have a sealed light engine is that dust particles can settle on the LCD panels. When a dust particle lands on and sticks to an LCD panel, it will produce a small, fuzzy spot on the projected image. When owners of projectors have a dusty environment and/or do not perform regular filter cleaning maintenance, they may need to send their units in for cleaning periodically to eliminate dust.

Sanyo has come up with a novel solution to this problem on the Z3. There are three tiny holes in the bottom of the casework that remain sealed in normal operation. However should a dust particle settle on an LCD panel, the user may remove the seals and insert a hand-pump blower (included with the product) that will dislodge any dust. After this operation, the seals are easily replaced and you are back in business."

That sounds like a pretty good idea. More projector should have this feature.

I have also added more commentary to my original post, so I thought I'd bump it up.

Thanks.

Thank you for posting this. I have two dust blobs but not on the screen itself, one of these days I will clean them out when I get the b_ _ _ _ to try this.

Is there a "better" can-type compressed air to look for? What do camera people use?

Is there a "better" can-type compressed air to look for? What do camera people use?Some (maybe all) of the common compressed air says "not recommended on camera mirrors". I have updated my original post under picture #4 to give credit to JeffKB for suggesting we test the compressed air against a mirror to ensure the spray is 100% clean. Below is what JeffKB wrote in the 4805 Official Thread (post # 11204):

At this point, the biggest disaster that could happen is that you spray some compressed air and a bunch of liquid shoots out. That would definitely ruin your day and certainly provide for The Moment Of Terror #3. So let's avoid doing that. How you ask? Well, what I did was to first spray the compressed air on a mirror. After verifying the mirror was still clean, I then moved the compressed air canister over to the PJ without tilting the canister in any direction.

The compressed air I used is called Air Doctor Blaster Co2, and it's for sale at Staples. So far it's worked well for me and it's oil free. Here is a link:
http://www.staples.com/Catalog/Browse/sku.asp?PageType=1&Sku=564124&bcFlag=True&bcSCatId=3&bcSCatName=Technology&bcCatId=6&bcCatName=Computer+Accessories&bcDeptId=1742&bcDeptName=Cleaning+Supplies&bcClassId=142034&bcClassName=Air+DustersTo answer your question, the CO2 canister is "supposed" to be the puriest and is what camera people use. However, the air seems to condense if you spray too long (maybe it is colder). Also, it is very hard to find in my area, but you should be able to buy it from camera stores. It cost 3-4 times more than regular compressed air. I started with it, but found it to be too weak, so I ended up using a the big canned air as well, following JeffBK's suggestion to test it on a mirror first.

My recommendation is just to use regular canned air, but be sure to following JeffKB's suggestion.

F$%K. Can't get that front grill off. The one right of the lense popped off easy but I can't get at the other two. =(

UPDATE: Damn, that took awhile. I eventually used a hairpin to pop the tabs. It was virtually impossible to see the tabs through the front grill. I had to kinda hold the bottem of the front grill away from the unit while shining a flashlight through the gap and put the pj on it's side.

It was virtually impossible to see the tabs through the front grill. I had to kinda hold the bottem of the front grill away from the unit while shining a flashlight through the gap and put the pj on it's side.I used the flashlight to locate one tab at a time. Once I saw where it was, without moving the projector, I used the spoon to blindly press and release the tab. The space is too tight to insert the spoon and still see the tab.

Once you've located the tab, you'll have to release it by "feel". You won't be able to see it with the spoon in the way.

Be very careful with your compressed air! I bought some that was for "optical equipment" etc. I sprayed it a few times not very hard. Seemed ok. However, I was cleaning the outside lense I sprayed a little harder and something sprayed onto the lense! I can't seem to wipe it off completely but it doesn't seem to affect the pq. No dust blobs anymore though!

No dust blobs anymore though!Congratulations on another success story!

More extensive cleaning:

(sorry, pictures next time I have to do this)

I made the mistake of blowing compressed air into the empty cavity where the lamp assembly goes one of the times I was cleaning my air filters. Big mistake. I ended up with a few dozen dust blobs. I did the procedure (very nice work on that!), but the back side of the large convex lens was filthy, as was the glass mirror at the front bottom right. The only way to really get to those is to take the top of the unit off.

1) Do everything above to get the lens out and front panel off.

2) Remove the two silver bottom screws on the back panel (these are similar to the ones on the front panel).

3) Remove the three screws on the jack panel. Two are by the component and composite / audio RCA jacks. The other is by the S-Video connector.

4) Get the back panel off by any trick you can (Spoon trick, etc.) There are three clips like those in the front, fairly evenly spaced across the back.

5) Flip the unit on its back and remove the 4 deep seated screws on the left and right edges (two on each side). These hold the top cover to the bottom through long shafts.

6) Carefully and somewhat evenly lift the top cover off, but be very careful as the control panel and built-in speaker are tethered to the rest of the unit via their data / audio cables. I recommend doing this on a bathroom / vanity counter with a mirror. Orient the unit so that it would be projecting on the mirror (away from you). Lift the lens end of the top cover up and watch in the mirror as you lift it toward you carefully. You will see the cables - make sure you don't yank on them. Flip the lid of the unit back and lay it upside down (like opening up a clam shell without breaking the two shells apart).

7) Above the light path, there is a metal cover. There are two black screws in the corners on the top part of this metal cover. There is another black screw down towards the color wheel. Carefully remove these and make sure you don't lose the washers on them. The metal cover has holes and alignment pins - you may have to get a fingernail or two between the metal and the plastic to pop this off.

8) You will now be looking down at the large convex (plastic!) lens and the angled glass mirror. You will notice that the large convex lens is held in place by metal clips. From this angle, you can clean the back of the large convex lens and get a good stream of air at the glass mirror. If, however, your stuff is so dirty that all you end up doing is moving dust around, then you need to go a step further (go to #9). Otherwise, reassemble everything in reverse order (skip to #14 for instructions) and enjoy!

9) Really Dirty: The metal clip holding the large convex lens in place is very easy to lift and disengage, but watch out as there is nothing holding it up through its holes in the assembly. It will fall down (but not through - phew!). You could try to secure it, but that may be more trouble than it is worth. Note how the bends in the clip are all pressed against the wings of the lens. It is possible to re-clip it at an angle such that only the top bends in the lamp side clip against the lens wings. You don't want to do this. Take a mental picture!

10) After uncliping the large convex lens, remove it and clean it. I actually used my lens cleaning kit for my sunglasses (available at "Sunglass Hut" or other sunglass stores). This kit consists of lens cleaning fluid, suitable for glass or plastic eye glass lens, and a microfiber cleaning cloth. After blowing off big dust with air, I sprayed both sides of the large convex lens and the cleaned it with the microfiber cloth. Do not stare at (through) that lens too directly or long - it will seriously give you eyestrain. To see how clean the lens is, turn off the lights and shine a flashlight at it obliquely (so that you get a reflection off the surface, not through the lens - remember that angle of incidence stuff from physics?) Make sure you don't leave any fingerprints on this lens - your skin oils will heat up on the lens and cause uneven heating, resulting in deformations / pitting in the lens. Once it is clean, set it aside. I also used this cloth on the main lens assembly (front and back) during the cleaning. Do not spray directly on that lens as some of the cleaning fluid could hit the lubricated areas of the lens assembly and react poorly. Spray the cloth and then wipe.

11) Before you put the large convex lens back in, clean the glass mirror (you will have more room to do this without the other one there). DO NOT spray directly on this lens, as it may bounce through the chassis and land somewhere you don't see. Instead, spray a bit on your microfiber cloth and then wipe the mirror down, and then go back with the dry part of the cloth. You should be able to get this mirror spotless in this manor.

12) If you continue to stare down at this thing, you will notice that the light from the lamp goes through the color wheel and then through a light pipe and is emitted from the end of that pipe, bouncing off the glass mirror and being manipulated through the large convex lens to eventually hit the DMD. I noticed the emitting end of my light pipe was awfully dirty too, so I cleaned it as well. I sprayed my microfiber cloth and wiped it clean (just like I did with the glass mirror).

13) Put the large convex lens back in. Notice that there is a chunk missing from it - that goes towards the lamp. There is a key peg that should nestle in on the top outer wing (toward the top of the projector, farthest from the lamp). Get the clip up and over the lens and make sure all the bends are pressing against the wings. I used a couple of tweezers to get it back up in place, and then used clean fingers to get it snapped in place. Be careful not to touch the large convex lens that you just made so clean! If you do, clean it again!!!!

14) Put the metal cover back on - make sure all the alignment pegs go back in their holes before you start screwing things. Don't lose those screws! I made sure I blew off this metal cover lest it dump a bunch of dust on my nice clean optics.

15) Flip the top cover back on and snug it back into place. Make sure it is clean first so you don't dump a pile of dust back in your optics. Screw the 4 screws back in their deep shafts.

16) Snap the rear panel back on. Screw the three panel mount screws back in. Screw the bottoms screws back in. Now you are back to the other procedure.


End result:
My picture is amazingly crisp and clean. The uniformity of the dust throughout the system was causing all sorts of light issues (hot spots / blobs / dark spots). My picture actually seem a tad brighter.

Quick question. If I have a dustblob outside of the actual 16x9 image, does that mean that I just need to mess with the lens? Or is it possible that the dust is on the mirror? I'd like to mess with the mirror as little as possible. Perhaps I'll just wait to do this until I get some more blobs and it's on the actual image. Man, this sucks. As much as I love the 4805, I think I'll go for a sealed optics model next time, or at least one that provides a legit method (doesn't void warranty) of getting rid of those little blobs.

Quick question. If I have a dustblob outside of the actual 16x9 image, does that mean that I just need to mess with the lens? Or is it possible that the dust is on the mirror? I'd like to mess with the mirror as little as possible. Perhaps I'll just wait to do this until I get some more blobs and it's on the actual image. Man, this sucks. As much as I love the 4805, I think I'll go for a sealed optics model next time, or at least one that provides a legit method (doesn't void warranty) of getting rid of those little blobs.
Sorry, those are most likely on the mirror. For whatever reason dust blobs on the mirror show up both inside and outside of the projected image. The good news is that this procedure will get rid of them.

As much as I love the 4805, I think I'll go for a sealed optics model next time, or at least one that provides a legit method (doesn't void warranty) of getting rid of those little blobs.In hindsight, I am glad I have the 4805 because don't have to worry about dust blobs and dirty colour wheels anymore. For me, these are DIY'able repairs on the 4805.

Even "sealed optics" may get dust blobs over time. At least with the 4805, I can how clean them myself.

I do agree that all projectors should have a simple user method of cleaning out dust blobs, similar to the Sanyo Z3.

This is just what I've been looking for. I've been putting up with dust blobs on my 4805 for a couple of months now. After reading the above, I had my projector dissambled, cleaned out, and reassembled in 30minutes start-to-finish!

Couple of things...

1) I didn't need to mark the positions of the focus and zoom wheels because it's pretty obvious where they go.
2) I never got the "lasso" method to work. I wound up popping them off with a screw driver.
3) After flipping the projector on its back and taking out the 2 screw on the bottom, I found I could open up the front plate enough to see the locking tabs directly. This made popping them open with a thin knife blade (inserted through the vent slits in the front) a snap.

In hindsight, I am glad I have the 4805 because don't have to worry about dust blobs and dirty colour wheels anymore. For me, these are DIY'able repairs on the 4805.

Even "sealed optics" may get dust blobs over time. At least with the 4805, I can how clean them myself.

I do agree that all projectors should have a simple user method of cleaning out dust blobs, similar to the Sanyo Z3.


Really? I didn't know "sealed optics" projectors could suffer from dust blobs. Then again, the 4805 is my first projector, I'm a newbie. Thanks again by the way for this great tutorial. I do have a couple blobs I'd like to get rid of. I'm just afraid of voiding my warranty or something.

Really? I didn't know "sealed optics" projectors could suffer from dust blobs.I have only read that it is possible to still get dust blobs on sealed optics, although the risk is greatly reduced. I really don't know for certain.

A small amount of dust is trapped inside the seal optics during manufacturing. However, it may not be detected by Quality Control if it is not actually on the LCD/DLP mirror.

Over time, the sealed optics unit is moved, tossed-and-turned during cleaning and lamp replacements, subjected to extreme heat and cooling, condensation, evaporation, etc. Eventually, the dust may be dislodged onto the LCD/DLP mirror.

Sealed units may not allow new dust to get in, but some amount of dust may already be inside the optics before it gets sealed.

I just added a new colour wheel cleaning guide to compliment this guide. Check it out here (http://www.avsforum.com/avs-vb/showthread.php?t=581503).

had posted this on the restoring of colour / brightness thread

"thanks a lot hugh2

have got the bust blob cleared with that procedure but now have got stuck with couple of other problems

1) my x1 is celing mounted an i have spacers to mark the point till which i screw in the x1 unit in the past whenever i took of the x1 and replaced it back on the mount there was no need to make any adjustments and my the picture would be displayed properly across the screen now when i mounted the picture is 2 " less on the right hand side and no matter what i am unable to increase the size of the picture

2) another thing that has happened i have to turn the focus ring completely on the right hand side (when facing the screen) for the picture to get sharper and there seems to be scope for more sharpness but the ring does not turn further again previous to the cleaning the focus ring would reach maximum sharpness with scope for the focus ring to turn on either side


3)nearly 1 1/2 feet on the near top right hand side outside the screen on the wall i am able to see 2 dust blob spots and also there a lot of light spill on the wall top of the screen

hoping that someone here would have some solution to my problem

thanks again for all the help

faiz, maybe you didn't reinstall and sit your lens assembly properly. Did you mark the posistion of the lens before you removed it?

no SuperGoop

i did not , damm , i should have
hope you have some advice for me to rectify this
looking forward to hearing from you all

thanks

I rotated my focus and zoom rings all the way out to maximize clearance to tie the string. Then I marked their positions with tape.

However, there is only one position to re-install the lens assembly, so I think that even if you didn't mark the rings, it shouldn't matter. Maybe your lens assembly is sitted unevenly. Try reinstalling it, making sure the 3 screws are tighten evenly and level.

Also, you can try removing the two rings and adjust focus and zoom without the rings. Maybe the rings were installed incorrectly, and are somehow not rotating properly, or are restricted.

I agree that marking the rings isn't that important for putting them together correctly. If you study the rings close enough you can tell how they fit together, almost like pieces of a jigsaw puzzle. Not doing it right would most likely cause the focus issue you're seeing. It should be easily correctable.

InFocus should provide a hole with a plug in the side or top of the unit directly in line with the DLP chip. It would be good for quick (if not thorough) cleaning and you could see the results live. I'm considering drilling one if I get the nerve to take the whole case apart. This assumes the integrity of the optical housing wouldn't be harmed.

In addition to hitting the chip with air, I stuck a (clean!) vacuum nozzle inside the unit and sealed the opening just enough to create a small ambient hurricane. It removed a lot of dust that would have just been kicked around inside, only to settle on the chip later. I vacuumed the vents first to make sure no dust was drawn in from them.

There have been mentions of projectors (other brands) with totally sealed optical paths, but it seems like that would create too much heat-buildup. Are they really made that way? I'm glad this thing is user cleanable, warranty violations or not.

It has been 6 months since I wrote this guide, and a dust blob returned. This time right in the middle of the screen!

Having already done the cleaning once, I was able to race through this cleaning in about 30 mins. As Nick_C said above, "I'm glad this thing is user cleanable, warranty violations or not".

This time, I attached my central vacuum with a small edge attachment and blasted the dust around while sucking it out. Kind of like a dentist rinsing your mouth while sucking the water at the same time.

The result: Better then my original technique. I think I got 99% of the dust out this time. Even when I project a black screen against a white piece of paper, I couldn't see any sparkle at all.

Before, even if there were no dust blobs on the screen, I'd still see at least a few sparkles if I hold a piece of paper close to the lens.

SuperGoop

Thanks for the Info...

I still haven't encountered a D-B (YET) but when the time comes for a cleaning, it's good to know that this thread will be my guide... :)

HH

SuperGoop,

I've been experiencing occasional color wheel buzz but everything else is optimal. I am hesitant to return it for repair lest getting refurb back with dead pixels, more noise etc.

From your firsthand observation of the color wheel assembly, does this look like a part that would be user serviceable? I am wondering if the buzz goes bad out of warranty, could I pull the CW unit, clean the bearings and use some teflon to lubricate?

Could you offer any input?

I only cleaned the colour wheel with Q-tips. I have no experience with removing it or lubricating it.

I also thought about removing it and giving it a thorough cleaning, but I have no idea how to remove (and re-install) it. I have not come across anyone who has removed the CW on the 4805.

Hi,
I have a Knool HD101 that is a SP-4800(X1) cloned.
I have 1 major dust blub.
IS it the same procédure for cleaning than the 4805 or can you point me where i can find it ?

Thx
Peper

Yes

Hi,

Thanks for sharing that procedure i have a Knoll HD101 wiitch is the same as infocus 4800. I got rid of the same problem you had with dust bulb.

I have cleaned image now !

Bravo
peper

I did it!! I actually did it! SuperGoop, if you ever come to Tennessee I will buy you a beer. I got my 4805 for a song with 30 hours on the lamp because it had a large dust blob. I decided I could live with it and I have- for 1700 hours!! But tonight I took the PJ down to take it to a party where we premiered a concert DVD I've been involved in and I used the opportunity to clean it and I figured, dang it, I'm gonna try and get that frickin' blob. Your instructions are perfect. The ONLY part that gave me trouble was getting the front grille off- it's REALLY hard to find those tabs. I gently worked the bottom far enough off that I actually got in that way- I found it easier to do than the front.

Anyhoo, I blew off all the accessible parts- mirror, DLP chip and color wheel. There was also a TON of dust and crud on the back of the lens plate. I decided not to tempt fate and did NOT clean the color wheel, from either side- I busted my X1 trying that and swore never again. My image is still plenty bright.

So, got everything reassembled and it works great! I have never had such a uniform image from this machine. There is actually still a tiny blob dead center of the screen but you have to really strain to see it. I may try to go after it some day, I may not. It really feels empowering to know this procedure- I feel like I should go out and rope some cattle or something *lol*

To anyone on the fence about this procedure, if you stay calm and go slow and refer to the pictures you can do it. screw the warranty *lol*

Thanks again!!

Just out of curiosity, has anyone tried a more primitive approach without taking apart the PJ? Like removing the lamp and sticking a home vacuum cleaner attachment tube in there, and let it suck away for 20-30 seconds?

joe

Turned on my pj today and a quarter of the left side is dark, it looks like something is blocking it. I looked into the lense and saw something covering some of the light and figured that something might have dropped or moved. So I took it apart and cleaned it out. I found out that covering object was that diagonal piece of metal that most definitely didn't move. It's stuck on there really tight. Put the projector back together and the left side is still dark! Could these be my bulb is gone? I would think that a dead bulb would just be completely dead, no light.

You'd think. I hope it isn't some failure of the DLP chip itself. Are you sure it's not input related (i.e., you have the problem on the startup screen and the blank screen function)??

Turned on my pj today and a quarter of the left side is dark, it looks like something is blocking it. I looked into the lense and saw something covering some of the light and figured that something might have dropped or moved. So I took it apart and cleaned it out. I found out that covering object was that diagonal piece of metal that most definitely didn't move. It's stuck on there really tight. Put the projector back together and the left side is still dark! Could these be my bulb is gone? I would think that a dead bulb would just be completely dead, no light.

I see the "diagonal piece of metal" you mentioned, but my image is fine.

Try to eliminate the simpler potential causes first. The closer something is to the light source, the less it would take to cause a significant obstruction to the projected image. So start with checking out the lamp housing and see if there's a sliver of anything blocking some part of the little "window" that let's the light through the lamp housing, or if anything came undone between the lamp housing and the color wheels.

From a post by TXJoe in the 4805 thread, there seems to be some sort of a wave guide somewhere in the light path that seems to amplfy the light before it hits the DMD. He said it's a rectangular tube - essentially - held together by glue at the edges (his problem was that the glue melted away.) Since you know how to take apart the PJ, you should make sure this wave-guide tube didn't collapse. If it became even just a little bit ajar, that, too, could cause the kind of obstruction you're describing (hope you weren't still under warranty - since you've already opened up the PJ.)

It's most certainly not the lamp - dead bulb wouldn't strike at all. But it sounds like you definitely have some physical obstruction in the light path.

Good luck.

Thank you very much! You saved us from many nights of a nasty spotty picture. Put me down on the long list of people who owe you a beer for this post.

Does anyone know if this procedure is similar for the InFocus 7205? In my attempts to clean the dust out of it recently I stupidly blew it all into the lens assemble and now it is covered and the picture has blobs all over it... grrrr!

FANTASTIC.!!!

Ive had the blob for about 2 months. I tried to take the unit apart, but couldnt figure out how the front assembly came apart. I was affraid I was going to break it, so I admitted defeat and reluctantly gave up. :o

When when exercise a little patience, do our research....use the search button......we find little gems like this.!! :D


Thank you for you time and effort.
Bryan

I hate dust blobs. I'm picky about things like this, so it was worth the risk. I wasn't even especially careful. I pried the rings off with a plastic knife without causing any scratches or scuffs. And I simply pried off the grill, as gently as possible. No problems.

When I got everything open, I sprayed compressed air in the general direction of the mirror. Then I slapped everything back together and powered it up. The 5 or so annoying dust blobs were completely gone! No trace whatsoever.

I did notice something that seemed quite bad - the little square glass window on the lamp housing is badly cracked. Strangely, this doesn't affect image quality at all. When you buy a new lamp, does it come with a whole new lamp housing? That would be nice, especially for the price.

SuperGoop, thanks a bunch for the walkthrough. I have an Infocus X1 and when my first bulb went out I accidently blew out my lamp area; therefore, leading to dust spots. Now I'm clean and clear again, thanks to your pictures.

I'm too chicken to try this but after replacing my bulb now I have a blob smack in the middle of the screen.

Turned on my pj today and a quarter of the left side is dark, it looks like something is blocking it. I looked into the lense and saw something covering some of the light and figured that something might have dropped or moved. So I took it apart and cleaned it out. I found out that covering object was that diagonal piece of metal that most definitely didn't move. It's stuck on there really tight. Put the projector back together and the left side is still dark! Could these be my bulb is gone? I would think that a dead bulb would just be completely dead, no light.This is slightly off topic ... which is why I originally PM'd you. But it occurred to me that I should post this. HELP ...

Here's the text of the PM I sent

Hi -

I've got the same symptom. Mine's on the right side. Blocked area is about 8-10% of the total screen area. The "edge" of whatever is blocking the light has a fair amount of chromatic aberation. In the blocked area, I can still see image ... it's just a lot darker.

I'm guessing either the reflective mirror (not the DMD) or the reflective plastic lens has shifted. Becuase all the image is still showing and the image has not shifted inside the 1.78 frame. It's like something is blocking the bulb's light before it reflects off the DMD.

Might this be the "Light Tube Failure" I've heard about? Or perhaps something has moved. Anyway, I'm guessing this unit is total'd. Gonna have to buy a new projector and then open this one up and see if I can fix it. Too bad ... I just bought a backup lamp 4 months ago.

Quick question ... have you recently sent your projector in for service? I did. I wonder if they screwed this up when they had it open.

Just bumping this to say a huge thank you. This guide is incredibly easy to follow, and my picture looks clearer than ever now. THANKS!

Thank you for those detailed instructions - I had to hound Infocus for several weeks until they called me with a link to YOUR thread.

I performed the procedure today and most of the dust spots are gone - I had a rainbow of dots all over my wall prior to cleaning - inside & outside of the 16x9 screen.

There is still one blob on the right, which I will try to clean the same way. However, I also notice...if I carefully look into the lense while it is projecting...that there is still a fine film of what appears to be dust on the main mirror. Is it ok to actually wipe off that mirror when it is disassembled...instead of just using compressed air?

Has anyone tried it? I don't want to crack that mirror!!

Many thanks!

Just two questions. If you do not have any blobs is it worth still blowing the projector mirrors with CO2? Will this improve picture quality in any way?Secondly, I have my projector connected to my laptop via DVI, it is recommended to have 56/28.5 for DVI connection. However, I will use DVE to calibrate the projector, should i keep the recommended 56/28.5 or change it according to DVE? Thanks.

Just wanted to say thanks again for making this great guide. I'm about to do the procedure for the second time in quite a few months. I'm not nearly as scared this time... =)

Thanks everyone for the feedback. I don't frequent this forum that much anymore, but it's good to know that the guide continued to be helpful.

This may be a stupid question but....can a dust blob cause any damage?

Mine bothers me, but I don't have the time to repair it (and have cats and dust that I just can't get rid of)...so if I wait on cleaning it, will it cause any problems?

HEEEELP !

AVe, PJgurus ;- ) got a prob w my great InFocus X2: The projected image is now partially grey shaded; about 30% of the screen on the left hand side of the projection. The inside edge of that shadow has two or three vertical strips of rgb colours.

The image still shows correctly... except this shadow. Seems that something is blocking the image from within the projector as if something within shifted.

I removed the bulb (1500 hrs), dusted, cleaned and cleaned all visible lenses+mirrors.
Might this be the before mentioned "Light Tube Failure"? Or mirror shift?
Anybody who knows...? I'd be grateful for any good advice :- ))

Just wanted to give my thanks as well for this post w/ instructions! I had previously removed the lamp housing to clean out the filter of the dust. Upon the next viewing, I had dust blobs galore! I found this post, and after about 20min + re-setup of projector, the blobs are gone!

My main hold up was the front cover tabs. I did not have any silverware thin enough, so I used a coat hanger, and presto! The trick was something sturdy and thin enough, the photos showed me where to line up to the tabs.

Thanks again! Now I have WAF again! ...but now I have to wait to get a new 720/1080p projector...hmmm...maybe not so good after all....

Someone gave me a 4805 that had a dark band on the left side. I took it apart and removed a lot of dust. Made it worse. Found this thread and learned about the light pipe. Fixed the light pipe. Two of the 4 mirror pieces were still together. I used some reusable adhesive putty to hold the pieces from moving and some cardboard strips as spacers and superglue from the kitchen junk drawer. Here's some pictures.

Thanks johnd393 for the light tube pictures. And thanks SuperGoop for the guide, sorry for straying slightly off topic.

johnd393 - I've been thinking about doing the light tube repair myself. Was the mirroring burned off the glass at all? One poster said that was a problem for him. From your pictures it looks like the side pieces aren't quite flush with the top and bottom pieces? Is that right? Based on what you saw of the design does how the top/bottom/side align together seem to require a high degree of precision?

Still enjoying the 4805 after 3 1/2 years and god knows how many hours. Getting -->|| this close to doing the light tube repair at my next dust blob cleaning session.

I'm laughing, because just yesterday I took my old 4805 apart and my light tube is EXACTLY in the same condition. I was wondering how to shape the repair... Your use of putty is a GREAT answer. I think the hardest part might be putting it all back together again, with no extra parts.

The mirrored surfaces were clear on mine. Also, it seemed apparent to me, that the mirrored surfaces go inside the pipe. The back of the narrow pieces is not flush with the edge of the wider pieces, which gives you a little notch along the edge to put the glue in. You don't want any glue to run inside the pipe. For what its worth, and this is not precise, the little cardboard spacers I made are about 3/16" wide. It seems that many people have done this so I think your best eyeball precision is good enough. If no pieces are still together, maybe under a magnifying glass, you could see a pattern in the old glue that would give you a idea how the edges fit. In the "PipeU.jpg" picture, one side is just held in place by the putty and cardboard. I set the top piece on and glued the edges than when the glue set I turned it over and glued the other edges.
Good luck

This is to funny I just took my 4805 apart yesterday and fixed the light tube:) The cardboard was a great idea along with the putty. I was lucky only 1 of the pcs was loose so I had the others as a guide to glue it back the way it was. I did add glue to all the sides so that I would not have any problems for awhile( I Hope )! Sure was a pain to get to. I really was worried about the color wheel braking in the process! I was able to get rid of most of the dust blobs but I do notice 2 really small ones I may have to try to fix that later! I am just soo happy not to I have to look at that stupid brown and yellow 6" mark down the right hand side of the screen! Besides now that I have had it apart the dust blobs are real simple to fix:D! The hardest part is removing it from the mount:rolleyes:!!

Thanks to everyone in this thread, I used the instructions and repaired my sp4805 with a broken light tunnel (2 of the 4 mirrors were loose).

Just to add, the repair does not need to be perfect, my light tunnel has burn marks and scuffs on it. However after putting it in, it's like being brand new.


And yes, I was very nervous doing anything near the color wheel ;)

SuperGoop, JohdD393 (and all),

Thanks for the great pics and info!

The cardboard insert was incredibly helpful and the measurement of 3/16" was dead on. I used it as a sort-of "handle" while doing the repair.

Anyone can do this repair, just take it slowly, and use all the great tips in this thread and the other great light tube repair thread (http://www.avsforum.com/avs-vb/showthread.php?p=10792432#post10792432).

IMPORTANT NOTE: If you have a light tube issue (without dust blobs), you do not need to remove the lens. See the light tube repair thread (http://www.avsforum.com/avs-vb/showthread.php?p=10792432#post10792432) in this forum first.

Also, if you do happen to do the light tube repair, you may just want to remove as much dust as you can while you're in there. When I completed my light tube repair and put it all together again, the dark band was fixed, but I gave myself a nice new dust blob. Had to take the projector apart again. But thanks to this thread, it was a piece of cake.

Thanks again to all who contributed!

I found another thread with more pics of the light tube repair. It's for a Infocus X1 but apparently very similar.
http://www.avsforum.com/avs-vb/showthread.php?t=618877

More extensive cleaning:

(sorry, pictures next time I have to do this)


5) Flip the unit on its back and remove the 4 deep seated screws on the left and right edges (two on each side). These hold the top cover to the bottom through long shafts.

6) Carefully and somewhat evenly lift the top cover off, but be very careful as the control panel and built-in speaker are tethered to the rest of the unit via their data / audio cables. I recommend doing this on a bathroom / vanity counter with a mirror. Orient the unit so that it would be projecting on the mirror (away from you). Lift the lens end of the top cover up and watch in the mirror as you lift it toward you carefully. You will see the cables - make sure you don't yank on them. Flip the lid of the unit back and lay it upside down (like opening up a clam shell without breaking the two shells apart).



When you remove the back cover, simply unplug the connectors from the speaker and the keyboard pc board...you can simply lift the cover off at this point.