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Don't dump your CRT RPTV! - Page 398

post #11911 of 12297
Thread Starter 
Flyback being involved would zap the entire picture and make it disappear, not just go into pincushion status. The pincushion effect is one of many that happen when there is absolutely no convergence compensation going on and you see what your set would look like without any.

Meaning the ICs are always the first most likely suspect, and you must go that route before anything else.

Unless you have time on your hands and would like to explore the NON most likely suspects first...!

smile.gif

I am always available for help on this repair. It is a very common one for CRT RPTVs, regardless of brand or model.

b
Edited by Mr Bob - 10/9/13 at 11:30am
post #11912 of 12297
What kind of price am I looking at for repair (roughly)?
post #11913 of 12297
Thread Starter 
Best not to talk $ on this site. I can tell you it's always less expensive if you do it yourself, and this is the kind of repair lots of owners do by themselves. Depends on whether you have confidence in your electronic repair abilities.

Contact me directly for my pricing. It is very reasonable, given the value of a fully watchable, fully functional Toshiba HDready. Even more valuable once fully tricked out, of course...

Bottom line, it's very affordable and anyone who does not elect to get his CRT RPTV fixed when all that needs to be fixed is the convergence, simply is not aware of the gold mine he's sitting on.

Also contact me directly if you'd like to do a troubleshooting hour on your set, to maybe pin things down a bit more.

b
post #11914 of 12297

I have a Philips 60PP9202/17F

Chassis DPTV305F

http://www.avsforum.com/t/1492142/problems-with-phillips-60pp9202-17f

I posted about it previously here.

 

I had to replace the coolant.

 

After replacing the blue & green coolants my image is much better. After reinstalling them the convergence was way off. I marked the yoke positions, but after fiddling with them and lots of multipoint convergence adjustments, I have it watchable. However, there is still an occasional blue / green line around things. It is extremely noticeable on text. It also seems to be worse on the top and bottom of the screen. The image is also tilted in certain spots and is too big for the screen. Subtitles get cut off and such. I assume this is likely to me fiddling with the yoke adjustments. Is there a proper procedure to adjust them to their optimal positions?

post #11915 of 12297
Thread Starter 
Not really, without the proper training. It's best never to take yokes off a CRT unless absolutely necessary. I just transferred a blue 12" gun from a warehouse projector to another one in the owner's home, and did it all without disturbing even one yoke or magnet ring. When I fired up the home set, the only thing that needed obvious attention was the optical focus, because the throw distance of the warehouse projector was a lot longer than that of the home projector, projector to screen. The convergence was very straightforward after that, was pretty much all it needed. It was as if it had never been moved. If I had disturbed the yokes, who knows how long it woulda taken. I didn't want to be the one finding out. Been there done that.

The yokes and all the CRT magnet rings have been placed there in their proper positions and adjusted very precisely by the factory, by trained and experienced experts who do it every day. They are the primary alignment system and are not there for their looks. You don't just slide them off and then slap them back on once your coolant changing op has been completed. They don't just sit there, you don't just mount them and forget them. They are there to be precisely aligned, they are what guide the beam itself.

Hopefully you marked it all well, so you can at least get back close to where you started, and didn't change any of the magnet ring positions relative to each other. The direction they go back on has to be exactly the direction they were originally, front vs. back. Those rings are usually held in place by a white glue of some sort or other relative to each other, and are not to be disturbed ever again, except by experts again.

Your yoke tilt determines the levelness of the 3 images. The placement of the sweep yokes affects the sizing of your pics. One set of the magnet rings do the centering of your pic, others do the astigmatism alignment.

Always start with the green and work your way to the other 2 colors. I usually then do red to the green, then blue to the red. If these objectionable colors are all around your text, it's a focus issue. If only on one side or another, it's a convergence issue.

Again, I am always glad to answer questions from owners if you want to give me a call and set up an appointment. This is a professional operation for professionals in the field, and only certain highly gifted individuals can get it right as DIYers whether they have help or not. And the smart ones call me ahead of time, before they get in over their heads or paint themselves into a corner.

You could use some professional assistance, I betcha.

wink.gif

b
Edited by Mr Bob - 10/14/13 at 7:33pm
post #11916 of 12297

I recently bought a Hitachi 57S500.  I vacuumed a substantial amount of dust out of the cabinet taking care to not damage the lenses.  I found that the green CRT is not working.  Set was described as "fully working" but at the price paid have substantial doubt and was unable to check when acquired.  I have some low/high voltage electronics background but no TV experience.  Where do I start to find what the problem is?  Have tried to browse/search the forums but am simply overwhelmed by the sheer number of pages.  Would love to rescue it and make it my primary TV.

post #11917 of 12297
Thread Starter 
I am always available for technical consultation. Just contact me directly, off board -

b
post #11918 of 12297
Quote:
Originally Posted by Mr Bob View Post

Not really, without the proper training. It's best never to take yokes off a CRT unless absolutely necessary. I just transferred a blue 12" gun from a warehouse projector to another one in the owner's home, and did it all without disturbing even one yoke or magnet ring. When I fired up the home set, the only thing that needed obvious attention was the optical focus, because the throw distance of the warehouse projector was a lot longer than that of the home projector, projector to screen. The convergence was very straightforward after that, was pretty much all it needed. It was as if it had never been moved. If I had disturbed the yokes, who knows how long it woulda taken. I didn't want to be the one finding out. Been there done that.

The yokes and all the CRT magnet rings have been placed there in their proper positions and adjusted very precisely by the factory, by trained and experienced experts who do it every day. They are the primary alignment system and are not there for their looks. You don't just slide them off and then slap them back on once your coolant changing op has been completed. They don't just sit there, you don't just mount them and forget them. They are there to be precisely aligned, they are what guide the beam itself.

Hopefully you marked it all well, so you can at least get back close to where you started, and didn't change any of the magnet ring positions relative to each other. The direction they go back on has to be exactly the direction they were originally, front vs. back. Those rings are usually held in place by a white glue of some sort or other relative to each other, and are not to be disturbed ever again, except by experts again.

Your yoke tilt determines the levelness of the 3 images. The placement of the sweep yokes affects the sizing of your pics. One set of the magnet rings do the centering of your pic, others do the astigmatism alignment.

Always start with the green and work your way to the other 2 colors. I usually then do red to the green, then blue to the red. If these objectionable colors are all around your text, it's a focus issue. If only on one side or another, it's a convergence issue.

Again, I am always glad to answer questions from owners if you want to give me a call and set up an appointment. This is a professional operation for professionals in the field, and only certain highly gifted individuals can get it right as DIYers whether they have help or not. And the smart ones call me ahead of time, before they get in over their heads or paint themselves into a corner.

You could use some professional assistance, I betcha.

wink.gif

b

 

Thanks for your timely response. I never removed the yokes. I changed the coolant without messing with the yokes. I have not even touched the red at all, as it had clean coolant. After putting the blue & green back together, the images was tilted, quite severely. I understood the yoke adjusted that, so I marked them and moved them until the image was "straight". However, even after that, it still is quite bad around the edges and the projected image is too large for the screen.

 

EDIT:  Maybe my terminology is off. I moved the two metal rings on the tube.

post #11919 of 12297
Quote:
Originally Posted by Liboicl View Post
 

EDIT:  Maybe my terminology is off. I moved the two metal rings on the tube.

 

 

Quote:
Originally Posted by Mr Bob View Post

Hopefully you marked it all well, so you can at least get back close to where you started, and didn't change any of the magnet ring positions relative to each other. 

 

Oops. :eek: 

post #11920 of 12297
Quote:
Originally Posted by Mr Bob View Post

I am always available for technical consultation. Just contact me directly, off board -

b

Mr. Bob, I have read enough on here to know you are the go to guy.  But it comes down to this: if I have to spend more than $75 to get this Mit working it is going to the curb.  Similar sized CRT RPTVs are available on craigslist for ~$150 and would be my next choice.  It's only saving grace will have been that it opened my eyes to the incredible bargain these sets are.

post #11921 of 12297
Thread Starter 
I thought you said it was a Hitachi.

Your max is a little low for what you need to get done. For that I will be glad to get on the phone with you and spill my guts, drawing from a lifetime of experience with these incredible beasts. If you're swift and quick on the uptake, in the time allotted I might even be able to coach you in the proper ways to clean your optics so you won't step on any landmines. I can definitely share my observations about what may be going on in there re. your missing green image, and guide you about it a bit.

But for getting any repair work done by a pro, that sum isn't really realistic. You might get lucky and find something that is simply disco'd in there tho, in which case you'd have a fully operational set and could make an informed decision about what to do next.

b
post #11922 of 12297
Quote:
Originally Posted by LastButNotLeast View Post
 

 

 

 

Oops. :eek: 


My main concern is the size of the projected image. Is there at least an easy way to get it to fit on screen?

post #11923 of 12297

My Hitachi has horizontal and vertical pots:

 

"H SIZE" on left.

post #11924 of 12297
Thread Starter 
Way, yes.

Easy way, no.

Overscan is endemic in these sets, they all came with it, to hide the flaws they didn't have the budget to design out. To truly get your pic to show up accurately on your screen requires the entire overscan reduction protocol. If you just do the height and width, the picture will get really messed up.

Sony is the only CRT brand I know of that doesn't really hose your picture when you resize it. All the others change the shaping of the picture when it gets resized, either by the sizing controls like Michael showed you, or by the shimming operation.

b
post #11925 of 12297
Quote:
Originally Posted by Mr Bob View Post

I thought you said it was a Hitachi.

Your max is a little low for what you need to get done. For that I will be glad to get on the phone with you and spill my guts, drawing from a lifetime of experience with these incredible beasts. If you're swift and quick on the uptake, in the time allotted I might even be able to coach you in the proper ways to clean your optics so you won't step on any landmines. I can definitely share my observations about what may be going on in there re. your missing green image, and guide you about it a bit.

But for getting any repair work done by a pro, that sum isn't really realistic. You might get lucky and find something that is simply disco'd in there tho, in which case you'd have a fully operational set and could make an informed decision about what to do next.

b

It is a Hitachi, got messed up reading other threads and looking at TVs for sale.  Well I'll open it again and look around, but did not see anything disconnected or even any components that looked scorched/swelled/etc the first time.  Might even pull the boards and look for bad/cold solder.  

Any words of wisdom for not getting bit by some High Voltage?  Many years ago in college our instructors cautioned us with the tale of a first year student that decided to fix his TV and hurt himself badly.

post #11926 of 12297
Quote:
Originally Posted by Mr Bob View Post

Way, yes.

Easy way, no.

Overscan is endemic in these sets, they all came with it, to hide the flaws they didn't have the budget to design out. To truly get your pic to show up accurately on your screen requires the entire overscan reduction protocol. If you just do the height and width, the picture will get really messed up.

Sony is the only CRT brand I know of that doesn't really hose your picture when you resize it. All the others change the shaping of the picture when it gets resized, either by the sizing controls like Michael showed you, or by the shimming operation.

b


Any suggestions for the Philips brand I mentioned? I want to be able to see my subtitles. Thanks for the help.

post #11927 of 12297
Thread Starter 
Quote:
Originally Posted by justwantinfo View Post

It is a Hitachi, got messed up reading other threads and looking at TVs for sale.  Well I'll open it again and look around, but did not see anything disconnected or even any components that looked scorched/swelled/etc the first time.  Might even pull the boards and look for bad/cold solder.  
Any words of wisdom for not getting bit by some High Voltage?  Many years ago in college our instructors cautioned us with the tale of a first year student that decided to fix his TV and hurt himself badly.

I can't really do any more without your signing up for a technical hour with me on the phone. It's not expensive and has been considered well worth it, to members of this thread especially.

b
post #11928 of 12297
Thread Starter 
Quote:
Originally Posted by Liboicl View Post


Any suggestions for the Philips brand I mentioned? I want to be able to see my subtitles. Thanks for the help.

There's the service menu only way and the shimming op way, which also uses the service menu. It would take a while either way. I can guide you on it by phone, and you would need to sign up for a technical hour on the phone with me for that. Or fly me in and just turn me loose on it, like so many others on this thread have done.

b
Edited by Mr Bob - 10/20/13 at 9:47am
post #11929 of 12297
Quote:
Originally Posted by Mr Bob View Post

I can't really do any more without your signing up for a technical hour with me on the phone. It's not expensive and has been considered well worth it, to members of this thread especially.

b

I agree - well worth the money and the time!

Dave
post #11930 of 12297
I have a Hitachi 51F520 which I've had since it was new. Bought it sometime around 2005 I believe. I used to work on Hitachi (and other) sets starting in the early 90's for a retailer. I've always been happy with the set and I know that Hitachi RPTs can last a LONG time. I've been contemplating replacing it with something newer but I came across this thread when researching the topic and it gave me some ideas. I know the wife will say "if it's not broke don't fix it" but honestly I've not been 100% happy with my picture quality for some time. I have never taken it apart to clean it so I think that will be my first step. The convergence on these things, even the consumer adjustment, is pretty decent but what I have noticed is that because the back of the cabinet is plastic, it is prone to some convergence issues due to heating/cooling, at least that is my take on it. The older sets never had this problem because the entire cabinet was made of particle board, although they were heavy, they were better suited to this type of set . I can spend 1/2 an hour or so re-converging it then the next time it gets hot in the living room, everything is thrown off. Anyway, I'm not really here to ask any questions (yet) just more trying to decide what to do. It is a HD set and does have one HDMI input so I'm set there, but it does not have an OTA tuner, well not a digital one. It's been 7-8 years since I stopped working on TVs and I'm not even sure I'd remember how to go about doing a setup and I know that I don't have the eye for it that I once did.........use it or lose it I guess. wink.gif I keep saying when the set dies I will replace it but I know full well that these sets can operate well into their twenties. Ours it not on 24/7 so we're not killing it.
post #11931 of 12297

There are a couple of threads specifically for us (Hitachi die-hards). Here's one:

http://www.avsforum.com/t/790702/hitachi-51-57-65f59a-crt-rptv-tweaks-thread

Here's your service manual:

http://www.manualslib.com/manual/68065/Hitachi-51f520.html

And you have Bob's phone number, so get to work.

;)

As you've probably read, Bob has hourly rates for phone consults. I replaced a CRT gun with him on the line. Since I don't solder, I sent him my board to replace my convergence chips. Even for a cleaning (okay, especially for a cleaning), I strongly suggest you speak with him.

And, now that it's taken you six years to make your first post, I hope we see more of you around here.

Michael


Edited by LastButNotLeast - 10/20/13 at 6:11am
post #11932 of 12297
Well then.........eek.gif
I've replaced a number of CRTs in older sets which were before digital convergence..........I think I have a cross hatch burned in the back of my retinas from it! I've also done many a convergence amp. and resistors aplenty. Thanks for the links, now I have NO excuse. I noticed a bit of burn in recently as my daughter has been watching her shows in non high def with 4:3 aspect...........not her fault, she's 2, but I have talked to my wife about it. I may get a chance to at least pull the screen and clean the lenses today, then I'll touch up the convergence and see where that gets me.
post #11933 of 12297

Be very careful. As Bob says, you only get one shot at those lenses - they're plastic. 

Leave the set in zoom mode for her; I doubt she'll complain about the overscan.

;)

post #11934 of 12297
Thread Starter 
Yes, welcome! You seem to know your way around these sets, my compliments!

You can reverse the slight image burn your 2 year old has put there if you know Powerpoint and can create a reverse image for the 4x3 imprint. After the required number of hours doing this "reverse burn", this will restore evenness across the entire screen again in your whites, and if it's in its early stages, you won't lose any appreciable light level over it.

The idea is to "burn" - to age - those areas that are not in the 4x3 area - the side bars areas, which have not received the same amount of aging as the center 4x3 section - to exactly match the same phosphor generation light levels as the 4x3 area now has. If you work with your Width control - shown in Michael's picture - and feather it in in the final stages of your reverse burn, you'll never see the line of demarcation either, between the 4x3 area and the side bars areas.

Be sure to mark EXACTLY where that Width pot presently is, because your entire geometry/convergence has been set to exactly that width point, and changing it will change the efficacy of your g/c. You'll need to set it back to EXACTLY where it started out, to get back to the garden.

Then as Michael says, use Zoom for your daughter's needs from now on. She'll probably like it better...

tongue.gif

Again, welcome! Sorry you waited so long!

wink.gif

b
Edited by Mr Bob - 10/20/13 at 8:58pm
post #11935 of 12297
As I recall if you leave the TV on for an extended period set to the tuner but not tuned to any channel (just static), you can fade the burn in that way too, not as precisely though as your method. I spent an hour or so this afternoon and took the screen off, cleaned the lenses inside and out and OMG!!!!!! It's a COMPLETELY different set! The contrast is through the roof, the colors are gorgeous and the detail is unbelievable. Satellite HD has improved since this thing was new. I put a Nemo Blu Ray on and I was blown away. I still need to do a few minor touch ups to the convergence but the magic focus even did a pretty good job. For the time being I'm very happy. Maybe I can watch TV again!
post #11936 of 12297

If you display static, you're just also burning the good phosphors. Having everything equally bad is not the goal. ;)

How noticeable is the problem?

post #11937 of 12297
Well that is the downside. It's pretty noticeable but I don't know if I'm going to worry about it too much right now. I'm just so enamoured with the picture right now that it doesn't bother me too much.
post #11938 of 12297
I have a chance to pick up this set but Im not even sure what model it is at this point. I know its a LG and its described as a RP set but Im not even sure if its a DLP or CRT even though it was described as a CRT. At any rate here is a picture of a set like it. This is one at a garage sale someone told me about and the guy said the pic was very nice and the set works.

post #11939 of 12297
Thread Starter 
DLPs have about half to 2/3 the depth of CRTs. They never had a shortened-width platform like in the picture, that was pretty much reserved for CRT, as far as I have seen. All the DLPs I have seen have the same size platform as view screen.

b
post #11940 of 12297
Thread Starter 
Quote:
Originally Posted by Inno View Post

As I recall if you leave the TV on for an extended period set to the tuner but not tuned to any channel (just static), you can fade the burn in that way too, not as precisely though as your method. I spent an hour or so this afternoon and took the screen off, cleaned the lenses inside and out and OMG!!!!!! It's a COMPLETELY different set! The contrast is through the roof, the colors are gorgeous and the detail is unbelievable. Satellite HD has improved since this thing was new. I put a Nemo Blu Ray on and I was blown away. I still need to do a few minor touch ups to the convergence but the magic focus even did a pretty good job. For the time being I'm very happy. Maybe I can watch TV again!


Great! So nice to hear someone extoll the virtues of optics cleaning besides me and a few choice insiders here...

The "snow" method of screenburn damage control is simply to make the line of demarcation get blurred a bit, so it's not so noticeable. As Michael says, that method dims ALL the phosphor levels, 4x3 area and sidebars areas alike. Not so with my method, which keeps the dimming of the overall picture to its absolute minimum.

Since screenburn is not real noticeable until you hit an all white scene, I am sure you can live with it for a while anyway, till you are ready to do it right.

Thanks for the vivid description of the benefits of your optics cleaning op. How exactly did you do it, what were your materials and methods, and when you said "inside and out", did that mean you cleaned each and every individual lens in each of the 3 focus barrels? Did you clean the mirror?

b
Edited by Mr Bob - 10/20/13 at 9:13pm
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