Quote:
Originally Posted by walterbeers
Working on a 13 inch Sony, which is dead except relay clicks. Shorted Horizontal output transistor D1396, ECG2302. I assume the flyback shorted the transistor which is a Sony 1-439-314-11. (flyback shows no signs of overheating, cracks, or smells) Also wondering if it took out the regulator/audio IC STK563F ECG 1732 Anyone ever just change out the transistor and have some luck with it powering up? I know most of these sets are throwaways, however it had a perfect picture before going out, and the set is super clean inside and out. I know most of the parts are available through e-bay, but reluctant to spend money on it. If it were just the transistor, it wouldn't be so bad. Any thoughts?
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Replace the transistor, and put a 60W light bulb in series with the collector of the output and flyback winding - if it the set comes on and the bulb is dim, you've likely fixed it. (Your pix may be shrunken, it's okay) If the bulb burns bright, you have any number of things wrong:
No Horiz drive - bad solder at the driver transformer, bad driver transistor, open resistor in drive ckt.
Shorted fly - pull it and ring it if you have a ringer (we used a VA62) or a HR machine.
Short in one of the scan derived supplies - secondary, lower voltage supplies off the flyback -open caps lead to shorted rectifiers, which leads to HO failure.
Other odd problem - mishapen drive pulse, poor B+ regulator, no regulator feedback, bad shutdown circuitry, or something else.