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Discussion Starter · #1 · (Edited)
Summary of steps / instructions:

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.


*** BEFORE ***






*** AFTER ***





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 below picture.




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).




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.




There are 3 locking tabs per ring. Use the lasso to pull one *tab* at a time. Do not attempt to pull the entire ring at once. It would be too tightly held. I borrowed D-Train's idea to mark the position of the rings with tape before disassembly.










Below, you can see the 3 tabs holding each of the rings.



 

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Discussion Starter · #2 · (Edited)
The lens with the rings removed. You can now see the 3 screws holding the lens assembly.




Remove the 2 screws on the underside holding the front grill.






Shine flashlight through grill to look for the 2 locking tabs (1 on each side), plus 1 more to the right of the lens.




Use small spoon to press down (do not pry) to *easily* release each tab. No need to pry or use force. If you have to use force, you are doing it wrong!







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.




Notice the grill deflects the hot exhaust away from the light path.




Remove the 3 screws holding the lens assembly.




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.

 

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Discussion Starter · #3 · (Edited)
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.






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.






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.






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.


Colour Wheel - BEFORE (notice the haze)



Colour Wheel - PARTIALLY CLEANED with alcohol and Q-Tips



Colour Wheel - CLEANED



SuperGoop
 

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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
 

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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.



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.
 

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

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



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


HH
 

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

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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.
 

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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
 

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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
 

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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.
 

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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!
 

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Discussion Starter · #15 ·
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.

Quote:
Originally Posted by Quaid /forum/post/0


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.
 

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Discussion Starter · #16 ·
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.
 

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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.
 

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Discussion Starter · #19 ·

Quote:
Originally Posted by stoked /forum/post/0


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):

Quote:
Originally Posted by JeffKB /forum/post/0


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/Brows...me=Air+Dusters

To 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.
 

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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.
 
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