Hello, I need help to troubleshoot a Y-MAIN board LJ92-01200A (LJ41-02759A) at the component level.
Prima plasma TV model PH42T7.
Initially, I found the two Y buffers defective, on the Y main a short circuit mosfet Q5009 (One of these 7 transistors in parallel), and a diode short circuit D5022.
D5022 is indentifies F6 5L.
I bought two new Y buffers boards, LJ41-02761A / LJ41-02760A, Q5009 I removed, and installed a 1N4007 diode (1 amp) at D5022.
I have not replaced Q5009 for now.
I installed Y upper board, and the Y main.
Turn on TV for 10 seconds.
Top side of the picture is good and clear.
I removed upper Y board, and installed lower Y board.
Bottom side of the picture is very bad, garbage on screen.
D5022 diode short circuit again. Something kill it.
I checked the Y buffers boards, no short circuit on both.
I tried a second time the same operation with a diode 2 amps, same thing.
What's going on?? All fuses are good.
Another component of the Y main is in fault?
Is it possible that IPM module (the big IC) is defective?
Thank you for help.
