Re: Philips TV model 20PT6245/37, Vertical Deflection Problem

Hi,

Here is an update, but TV is not repaired yet:

Note: TV chassis is L03.1UAA and I have SM.

The vertical deflection system uses discreet components. There is no vertical amplifier IC, which is common in all other TVs I have worked on. I replaced "2463" 100/50 and "2446" 470/16. Both measured a loss of capacitance, but it made no improvement. "2465" 10/160 tested very good, however I replaced it, but it didn't fix the problem.

I tested the two output transistors out of circuit (AOK). I tested other transistors in circuit. Also tested various components in the vertical deflection circuits. Note: I originally checked solder joints and soldered several joints that seem to lack good solder bond.

I used a Yoke tester and checked both windings individually after I separated the windings at a terminal. Both windings read "good", but one winding had a higher reading than the other. I repeated the test incase of a poor test lead(s) connection, but the results were the same!

Sc>Hi,

tested other

dered

ts

l doesn't

l is

he

know what

ection,

, but

d tapping

e quoted text -

If you have a scope, it and a dc voltmeter, you should be able to check the voltages on the output transistors to make sure they are biased correctly and then check the waveforms. If you don't see any sawtooth at the output of the pair of output transistors, that's your problem. If you do have a sawtooth there, then maybe the capactior coupleing the output to the deflection coils is open/

Bob Hofmann