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Sanyo CRT-tv. HOT tested bad. Transformer noisy. What next?

Sanyo 35" CRT Mod # DS35590.

PROBLEM: No pic or sound, only the steady, high-pitched whine. Not very loud. Only unplugging the set stops the noise. Power button ineffective. Used small tube-in-ear stethescope method to find sound - sound is from transformer nearby, for sure. This is NOT the FBT, it's the other one. Main power T'former I suppose. HOT tested bad. So i know I need that. Checked solders. No bulging CAPS. Gut says replace FB & HOT and run with it. BUT, is transformer noise related? Please advise. Thx. Kevin.

UPDATE!!! Just swapped out bad HOT for known good one (different spec's, from a 32" toshiba crt, but a good HOT). Result is that the high-pitched whine from the T'former turned into a rapid 'tick' or 'click' sound and at relatively the same volume. Probably 30 cycles/ sec. Does this help? Is this transformer a problem with it alone, or is it brought on by failed HOT and/or FBT. I need to know what else to check. Don't mind replacing HOT and FBT, but don't wanna miss anything either. Thx. Kevin.

Reply to
Meatman
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Make sure you replace the electrolytic capacitor off of the horizontal drive transformer. Chuck

Reply to
Chuck

I think you're in the right direction, could be the FBT at fault. At any rate, there is probably something loading down the line output stage. check the diodes in the lines of supplies derived from the FBT secondary.

Have you eliminated the PSU? Check the psu secondary side for shorted components or open resistors. You need to make sure the B+ line feeding the line output stage is correct.

As chuck says, check the horizontal drive circuit and especially the solder joints. Change the cap (often a polyester film type) between c- e on the HOT or it will probably blow again.

Let us know how you get on!

-B

Reply to
b

Me, OP: Ok, so I have some work to try to do 8^) Please clarify right quick: Is the SMPS suspect at this point? Or can it reasonably be eliminated as a likely problem? Just your best experienced guess. Thx again. Kevin.

Reply to
Meatman

y

the whole point of the tests described above is to eliminate things, including the smps. Until you check the secondaries, who knows?

-B

Reply to
b

OP: Ok, I'm merely learning. I know what you mean secondaries, in principle. But I have to find them first! Seriously, I'll do some lookin' around and try to find a schematic and see what I can gleen. I know this isn't a DIY hand-held 6-week course on CRT repair. I'll let you know. Any last info, guys? Thx, Kevin.

P.S.

Reply to
Meatman

p.s. R413 - no voltage

Reply to
Meatman

You need the chassis reference - look on the main pcb. I searched eserviceinfo for the model number, but nothing there. Having the schematic would help you trace the lines, for sure!

-B

Reply to
b

In general, or best recollection for my Sanyo, can you approximate the typical locale of the numbers I'm looking for on the PCB? Maybe the basic format in general? I see a few likely candidates.

Reply to
Meatman

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