Sony KV-27S36 HV-to-flyback connector

Does it look like it's designed to come out? And what kind of repair do you think you can perform upon it once it's removed? Unless the cable end fits into a socket say like an auto distributor there might not be much that can be done other than replacing the flyback.

This sounds more like a vertical deflection fault rather than a horizontal fault. I have my doubts has anything to do with the flyback, unless it is one of the supply voltages from that section.

Most of the common failures in your model series for this type of fault are many of the electrolytic caps and cold solder connections to the output devices since they run very hot.

Use a heat gun and circuit freeze to troubleshoot for the fault. Heat the caps in the vertical deflection area, and then test them with an ESR meter. You can then use the circuit freeze to test the questionable caps in the cold state after you find them to be failing from heat.

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JANA _____

The problem does not always arise on every viewing session.

It does not seem to be particularly temperature sensitive, in that spraying "duster" air-in-a-can (which can come out quite cold!) on suspect areas seems to have zero effect.

Poking parts with a stick also seems to have no effect once the problem starts, but after the problem goes into remission (after power cycling), poking at the HV cable where it emerges from the flyback brings the problem back.

Assuming that there is something flaky about that connector, I thought I'd just inspect and repair or replace it. But the cable only wiggles up and down slightly, and I am uneasy about giving it a serious yank. So, is this supposed to come out with a yank, or is there some secret? What sort of connector is down in the hole?

Many thanks for any help and advice!

Bob Masta

D A Q A R T A Data AcQuisition And Real-Time Analysis

Scope, Spectrum, Spectrogram, Signal Generator Science with your sound card!

Yes, it does look like it's designed to come out... looks exactly like an auto distributor socket complete with rubber boot that can slide up the cable. Since it seems to be quite sensitive to motion, I assumed (hoped!) it was just a flaky connection.

Best regards,

Bob Masta D A Q A R T A Data AcQuisition And Real-Time Analysis

Scope, Spectrum, Spectrogram, Signal Generator Science with your sound card!

Thanks for the advice. I will certainly check into these things. I agree the problem sounds like vertical deflection, but I am trying to work with the fact that I can bring it on by gently poking the HV cable at the top of the flyback. Doesn't seem to be enough motion to be wiggling the whole flyback and thus flexing the circuit board, etc.

Best regards,

Bob Masta D A Q A R T A Data AcQuisition And Real-Time Analysis

Scope, Spectrum, Spectrogram, Signal Generator Science with your sound card!

Some replacement flybacks require you to reuse the original HV cable. On those flybacks, they cable has about 1/4" stripped which is inserted in a one way gripper. Once it's in, there's often no way to remove it without breaking it. While extracting it from the old flyback, the stripped part of the wire often breaks off. The good news is that since it doesn't pull out easily, it must be making good contact with the gripper. If there was a bad connection there, you would see the picture get bigger and dimmer then snap back to the way it should be and you would hear arcing coming from the bad connection.

Have you re-soldered all the bad connections? Those sets often have many bad solder connections all over the main board. Be sure to re-solder the horizontal drive transformer (off the base of the HOT). It often doesn't take much to make a bad solder connection act up. The bad connection can be far from the part of the board which seems most sensitive. Andy Cuffe

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