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35" proscan problems (horizontal lines/turns off/high pitch whine)

Hi everyone. My friends and I got a 35" Proscan TV for free to replace a broken Zenith 20" CRT (the picture is green and brigher parts "bleed" over). I digress...in any case, the Proscan has problems. When i turn it on, the green LED by the power button lights up, but there is no image except for a few horizontal lines in the middle of the screen than bend a little; it looks like |) rotated 90 degrees. After a second or so, the green led turns off and so does the TV. When its doing this, there is a quiet high pitched whine. Sometimes it will try to cycle on and off a few times before giving up. Does anyone have any idea what's wrong? Can we use parts from the 20" Zenith to fix this? I have soldering experience and basic electronics repair skills. Thanks!

Reply to
playstationdude
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You won't be able to repair it with basic skills.

Reply to
Meat Plow

Thanks for the vote of confidence. Seriously, does anyone have any ideas what I can try? I have a multimeter and an oscilloscope. Its going to be recycled if I cant fix it. Thanks

Reply to
playstationdude

I'm just being realistic. You need more than a scope, a meter and basic skills.

Reply to
Meat Plow

That's not necessarily true, gotta start somewhere, and CRT displays are generally not too hard to work on. I don't have any specific advice for this set, but I'd start by checking all the semiconductors in the horizontal drive section as well as look for bulging electrolytic capacitors.

Reply to
James Sweet

I rarely use anything more than a multimeter, basic troubleshooting skills, and occasionally a tip from someone here. I've fixed dozens of TVs and monitors over the years.

Reply to
James Sweet

This part is what I had some trouble digesting:

quote: "Does anyone have any idea what's wrong? Can we use parts from the 20" Zenith to fix this" end quote

You in all your experience may think that these sets are "not to hard to work on"

Not the case for the totally clueless.

Reply to
Meat Plow

this

The OP might be able to fix the set, but given the problem, as he describes it, he'll probably need to shotgun a lot of components. And that's not the way you usually fix things.

Without at least a comprehensive service manual, he's likely to have trouble.

Reply to
William Sommerwerck

You might start by posting the model number and chassis number. If you want a color by numbers fix you need to be more specific.

Leonard

Reply to
Leonard Caillouet

Maybe just resolder the coils in the horizontal drive circuit...

Mark Z.

Reply to
Mark D. Zacharias

Ok, get back with the OP and tell him how to fix it.

Reply to
Meat Plow

the model number is PS35182 and the chassis is CTC170MA. Is there any more information i can give?

Thanks

Reply to
playstationdude

It is a CTC170 chassis. Even an experienced technician with the service manual would have a tough time with that one.

Do a google groups search for the CTC170 chassis and see what comes up.

Before you toss the set, find out if any repair shops are willing to pick it up for free.

Reply to
dakdak

want

Did a google search and found this site:

formatting link

more specifically: Proscan PS35682 CTC170 cycling on an off CTC170 chassis. Unit will cycle on and off three times then finally shut off. Gave tech instructions relating to the this type of shut down complaint. The 9 volt source was OK. The 3.7 volts that must be on pin 2 of U3101 (CPU) never rose above .8 volts. These two voltages are critical to the operation of the D.C. detect circuit. Problem was U1902 audio output IC on audio board.

Does anyone know where I can get circuit diagrams for the set? Thanks

Reply to
playstationdude

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