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sony kp-53s25
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PostPosted: Mon Apr 04, 2005 7:20 pm    Post subject: Found my fix Reply with quote

Just wanted to repost what I found to fix my sony kp41s25 dead set.

Everytime I powered up the set, it would just click off (shutoff) after 2-3 seconds.

I took out the G board (power board) and after some extensive testing, found out that the protection circuit was shutting off the circuit. An unloaded test showed that my 11v and 7v were about 4v over.

At this point I manually inserted a 100ohm resistor at the protection latch transistor to keep it from being activated by the protection circuitry.

Now my set is up and running! I will go back, remove the G board, and figure out exactly who is enabling the protection latch transistor, that way when I get a serious surge, my set is still protected.

Hope this helps.

-Dan
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mark



Joined: 20 Jan 2005
Posts: 43

PostPosted: Thu Apr 07, 2005 12:25 am    Post subject: Reply with quote

NEVER DEFEAT A PROTECT CIRCUIT AND RUN THE SET FOR MORE THAN A FEW SECONDS

if its unloaded they will be over.
BE AWARE:
some of those sony supplies cannot be tested without a load, without totally self destructing!

but, your on a path at least.
its probably an over current issue, or a component has gone leaky.
look for leaky diodes, ect.
it IS possible you have a false shutdown. it does happen.
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Dan
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PostPosted: Tue Apr 12, 2005 3:08 pm    Post subject: Reply with quote

Thanks for the warning mark.

You are correct that this did lead me to a good path...perhaps the long way but I did finally figure out that I needed to replace two convergence IC's on the D board.

Appearantly the H source was applying -15v to the green, whereas it should have been between -.5 to +.5 VDC (I beleive the spec calls for 0.413v) .

Throughout the years, one of the channels in the covergence IC's must have gone through breakdown and was shorted. So I really only need to replace one of the two IC's, but while I'm at it, minus well replace both, since they are the same, and for some goofy reason, sony designed the green convergence circuit to use one channel from each of the IC's... for V and H.

I only found out by manually forcing the powersupply to turn on disregarding protect line.
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Dan
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PostPosted: Tue Apr 12, 2005 3:12 pm    Post subject: Reply with quote

Thanks for the warning mark.

I did put a load on each of the pins to make sure that it resonates to its designed voltages, while bench testing.

You are correct that this did lead me to a good path...perhaps the long way but I did finally figure out that I needed to replace two convergence IC's on the D board. (model# STK392-010) between $8-$20/ea. depending on where you go.

Appearantly the H source was applying -15v to the green, whereas it should have been between -.5 to +.5 VDC (I beleive the spec calls for 0.413v) .

Throughout the years, one of the channels in the covergence IC's must have gone through breakdown and was shorted. So I really only need to replace one of the two IC's, but while I'm at it, minus well replace both, since they are the same, and for some goofy reason, sony designed the green convergence circuit to use one channel from each of the IC's... for V and H.

I only found out by manually forcing the powersupply to turn on disregarding protect line. I have to beleive this is how the pro's do it also, unless they have external powersupplies to bench test only the boards they are after....

Dan
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Jason
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PostPosted: Tue Jun 07, 2005 11:18 pm    Post subject: KP53S15 Reply with quote

I know its been awhile, I got tied up fixing my car too. Well here's whats going on. The last thing I did to this set was replaced the IC on the U board, also no luck. Its weird. I could disconnect the U board from the M board and the set would turn on. The picture comes on, BUT without any tuner (no channel static or anything). The channel numbers are still displayed and I could go through the menu and stuff, but what good is that without the tuner or video inputs. Now I'm checking caps (fun). Its my friend's TV and she said there's no rush, but I just want to get this done and over with.
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Paul109
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PostPosted: Wed Jun 08, 2005 8:25 pm    Post subject: standby Reply with quote

Having similar issues. First the screen went bad, replaced the convergence ICs and all good again. Then it would'nt go into standby properly (I'd see thin red lines across top of tele) and now it won't come out of standby. Clicks and then continually flashes...

Is this protection cct on a board, should I go recheck all the diodes around convergence ICs or is this showing problem on a different board now ?

cheers !
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PostPosted: Sat May 06, 2006 9:05 am    Post subject: Re: sony kp-53s25 Reply with quote

ANYBODY KNOWS HOW TO ENTER CONVERGENCE ADJUSTMENT ON THIS MODEL. tHE MIDDLE PART OF SCREEN IS OK EXCEPT AT BOTH SIDES ,THE RED LINE DON'T CONVERGE W/ THE REST OF THE COLOR HORIZONTALLY. THAK'S FOR ANY HELP. RICHARD
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gamegin
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PostPosted: Sat Jul 11, 2009 1:50 am    Post subject: Re: sony kp-53s25 Reply with quote

mccastlej wrote:
I have a sony kp-53s25. It only stays in standby. When I first plug it in a relay in the power supply section clicks, then over by the one of the flyback transformers there is a neon light that just flashes for a split second. When I try to power it up, it does the same thing. I cannont get this TV to do anything more than that. The standby light will flash when it is plugged in, but nothing more.


hello my sony kp-53s25 is almost 10 years old and while i was changing from video 1 to video 2 it quits on me no sound no pic just standby flashing when turned on and i hear a click..anyidea what is going on and how much would it cost to fix? i can't find anyone in hear to fix this big screen projector video tv....please help
thanks
gamegin
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PostPosted: Mon Jul 13, 2009 5:14 am    Post subject: Re: sony kp-53s25 Reply with quote

Anonymous wrote:
ANYBODY KNOWS HOW TO ENTER CONVERGENCE ADJUSTMENT ON THIS MODEL. tHE MIDDLE PART OF SCREEN IS OK EXCEPT AT BOTH SIDES ,THE RED LINE DON'T CONVERGE W/ THE REST OF THE COLOR HORIZONTALLY. THAK'S FOR ANY HELP. RICHARD



My TV have same problem. If your problem is solved please let me know how you solved. or somebody help us.
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