Riddled TV Repair Forum

crfonck · Joined: 19 Dec 2011 Posts: 3 Location: Iowa

Just picked up an older 55" Philips projection that needs some work but can't figure out yet what is wrong. The TV tries to turn on but there is no picture, just a clicking sound. The person we got it from mentioned it may need a convergence kit.

Does that seem like a correct assumption given the symptoms, or is there not enough info to diagnose properly? Just need a direction to start with. Any help would be appreciated.

Thanks
Chris

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crfonck · Joined: 19 Dec 2011 Posts: 3 Location: Iowa

Had a chance to plug in the tv to find out more symptoms. There is a squeak/click that happens every second coming from somewhere near the middle of the base circuit board. After about a minute of doing this, I can press the on/off buttom and it then flashes 5 times in a row, then repeats this pattern.

Any ideas on the issue? Really need some help and direction on what needs replacing.

Thanks

CelicaSupra · Joined: 30 Nov 2011 Posts: 15 Location: Crewe

Lifted from www.kellerstudio.de/repairfaq/sam/tvfaq.htm#tvdttttfff

Dead TV with periodic tweet-tweet, flub-flub, or low-low voltage

A TV which appears to be dead except for a once a second or so tweet or flub usually indicates an overload fault in the power supply or a short in one of its load circuits. In some cases, the low voltage (including B+) will just be reduced to a fraction of their normal value as a result of an overload on one of the outputs - usually the main B+.
This may be caused by a shorted rectifier in the power supply, flyback, or even the yoke, but check the the loads first. Wait a few minutes for the filter caps to discharge (but stay away from the CRT HV connector as it may retain a dangerous and painful charge for a long time), use an ohmmeter across the various diodes in the power supply. Using an ohmmeter on the rectifier diodes, the resistance in at least one direction should be greater than 100 ohms. If it is much less (like 0 or 5 ohms), then the diode is probably bad. Unsolder and check again - it should test infinite (greater than 1M ohms) in one direction.

Summary of possible causes:

Bad solder connections.
Other shorted components like capacitors.
Other problems in the power supply or its controller.
Bad flyback.
Short or excessive load on secondary supplies fed from flyback.
Short in horizontal yoke windings.
Problem with startup drive (cycling on overvoltage).

Hope this is of some help to you

crfonck · Joined: 19 Dec 2011 Posts: 3 Location: Iowa

Thanks for the reply. That helps quite a bit. Sounds as thought fixing may be a little over my head...never tested and done a repair similar to this on electronic equipment.

For a projection TV, is this possibly an easy or worthwhile fix if taken to a repair shop, or too costly given the type of tv it is?