Off Topic: Sony 50" rear projection TV

horseboy

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I have a 9 year old 50" Sony rear projection TV that has been working great for a long time. Yesterday when I woke up the center of the screen was collapsing vertically making the screen look like a bow tie. The three colors are also off from each other. They are converged fine in the center of the screen, but get further and further off the closer you get to the sides. One color fills the screen (the bow tie picture portion of the screen anyway), the next color is slightly larger and the other color is even bigger.

I really don't want to get a new TV right now. Anybody have any idea what the problem might be?
 
Sounds like a blown convergence IC. Look for a large heatsink with a IC on it with about 20 pins. Part # usually starts with STK392-XXX . There should be 2 of them.
 
Sounds like a blown convergence IC. Look for a large heatsink with a IC on it with about 20 pins. Part # usually starts with STK392-XXX . There should be 2 of them.

Thanks buddy. I'll crack her open when I get home and give it a look.

If that is the case are these ICs available, or is it a lost cause?
 
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You have to be careful... most of those are cheap knock-offs that won't last (or work at all). I trust this place:

http://www.acme-sales.net/

Also note that some substitutions are possible. For example, my TV came with STK392-560, but they can be replaced with STK392-570 (which are more available, and therefore less expensive).
 
How in the hell do I get to the tubes to discharge them? There is a ton of stuff in the way and I can't even see the anode caps. This is much more daunting than working on a regular arcade crt.
 
When I changed the ICs in my 56" Sony, I just left it unplugged for a while and disconnected the boards that had the ICs on them to work on. There was also some pico fuses and convergence resistors that needed to be replaced also.

I got my complete kit from here:
http://www.tvrepairkits.com/xcart/home.php?cat=1444

Might not be the cheapest, but the kit includes the genuine OEM convergence chips, plus instructions and support.
 
It has been unplugged for 3 weeks. I really don't want to get shocked.
 
Mine was unplugged for maybe 4-5 days. No shock to me, you'll be fine. But, I wouldn't go touching the anode or flybacks.

Try the kit out. I think they are around ~$65. Sometimes when the ICs go out, they pop some of the pico fuses and/or convergence resistors. It's best just to buy the kit and replace all parts.
 
Try the kit out. I think they are around ~$65. Sometimes when the ICs go out, they pop some of the pico fuses and/or convergence resistors. It's best just to buy the kit and replace all parts.

Replacing all the pico fuses and resistors is a lot of unnecessary work. Those components are easy to check with a meter to see if they're still good.
When I fixed mine the only thing that was bad was one convergence IC (cost $20). I bought two ICs expecting to replace both, but ending up keeping the second one as a spare. I could see why the one chip failed prematurely... it wasn't connected to the heatsink as securely as the other. The heat-sink compound was not applied evenly across the entire interface.
When you put the new chips in make sure you've got a good thermal connection to the heatsink (before you solder any pins).
 
Leaving it off for just a day is fine... it will self-discharge in that time. Not a big deal anyway, as you're not going anywhere near the HV section.

That makes me feel better. I'll be diving in this weekend.
 
Whats the Model Number?
on the back of set.
I may have the service manual I could send over.
Need to loosen all the wire cables from there purse locks
around the fly,along front of boards Etc so you can
pull out and up the chassis to get to the parts.
to desolder Both Ics and check the pico fuse's/ resistors in the
convergence circuit. Or replace the convergence board.

Its a good idea to replace both ics at the same time for a matched
pair and check the low ohm resistors haven't increased in ohms or open up.
Then after repairs you can press Flash Focus for auto convergence
to complete.
 
KP53HS20


Ha. After all these years I guess I forgot it was a 53 inch.
 
KP53HS20


Ha. After all these years I guess I forgot it was a 53 inch.

Maybe this will help.
http://www.tvrepairkits.com/xcart/product.php?productid=19945&cat=1513&page=1
convergence-repair-5-39.jpg
 
Do I have to desolder the flyback to get this board out?
 
Do I have to desolder the flyback to get this board out?

Nah, i think there is a way to disconnect the flyback from the anode caps on projection televisions if I recall correctly when I read over some repairs made on projection televisions......Was looking to fix my convergence issue on a arcade cab rear projection monitor.....just turned out it was the game in the end, fixed itself.

The one log I saw was kinda a push to click and lock in setup. You basically just grab the wire right above the cap on the flyback and push it inwards and then twist and it should release. I'm not a 100% certain that is what they all act like. That might just be the focus and brightness controls where all the flyback leads meet before they go to the tubes' anode caps that the technique works on........
 
Do I have to desolder the flyback to get this board out?



Pm me your e-mail for the service manual.
No need to remove the D board. Or fly just open up the purse locks.
You just loosen the cables so you can pull the chassis back.
Nothing to do with the tubes or anodes cup's.
the chassis will standup after cables are loose. Don't pull out any plugs connectors.
Don't remove the HV/convergence board,unless you want to replace it.
and you will have to remember alot of connectors to putback.
remove the Ics and ohm the fuse's any of them OPEN?
To check any of the resistor around the Ics just remove solder from one leg to check the ohms.I would just suspect the Ic's,maybe a fuse.Good Luck!
 
Nah, i think there is a way to disconnect the flyback from the anode caps on projection televisions if I recall correctly when I read over some repairs made on projection televisions......Was looking to fix my convergence issue on a arcade cab rear projection monitor.....just turned out it was the game in the end, fixed itself.

The one log I saw was kinda a push to click and lock in setup. You basically just grab the wire right above the cap on the flyback and push it inwards and then twist and it should release. I'm not a 100% certain that is what they all act like. That might just be the focus and brightness controls where all the flyback leads meet before they go to the tubes' anode caps that the technique works on........

Yeah, I read basically the same thing. I tried for quite some time with no luck.
 
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