Toshiaba 50HP66 Plasma SUS Board Question

[TECHMECH]

Hello, I have a Toshiaba 50HP66 which uses the common 50" 50x3 panel. I acquired this tv with the intention of repairing it. It originally had a flashing/scrambled picture. I replaced the ysus board (as it was making noise and cold). After replacing the ysus board and checking the buffer boards for shorts, I powered on, adjusted the pots to the correct voltage.

The picture has improved, but now upon pressing the power button I get a white vertical line/lines that move across the display then a colored/blurred mis-discharge type image, finally the tv powers itself off. I suspect the zsus board as a failure because I hear a clicking noise coming from the zsus after the power off. The vsus drops from 250v (measured at the zsus board) to 60v. When I disconnect the cable going from ysus to vsus the tv will stay on. Again, I suspect the ZSUS board failed at the same time as the YSUS, but this does not explain the white vertical lines that move across the display.

I hope someone knows the answer to this and can tell me if it is indeed the zsus or possibly the xsus at fault.
Power supply measures properly at 196v, what seems to be happening is an overvoltage on the zsus tripping something and dropping the voltage, forcing the tv to shut down.
Thanks in advance guys!

[cadiman]

Re: Toshiaba 50HP66 Plasma SUS Board Question

Unplug z board and see if power supply stays on. (You won`t have a picture)

All pdp voltages are on the back of the pdp, upper right or left hand corner for va and vs, etc.

There should be plenty of old posts for this L/G panel that will get you to the training manual.

Good Luck!

[TECHMECH]

Re: Toshiaba 50HP66 Plasma SUS Board Question

Update:
I have replaced the ER IPM and the TV now will stay on without shutting itself down. I still hear a clicking noise from the lower part of the Zsus Board. Voltages are now stable attached are pictures in the order they display onscreen.

I hope I attached the pictures properly using the manage attachments.

[rayrod81]

Re: Toshiaba 50HP66 Plasma SUS Board Question

If I remember correctly then your Vs is way too high. I think on these panels the Vs should be about 206V or close to that. A Vs that is that far out of spec will cause the set to shut down.

[rayrod81]

Re: Toshiaba 50HP66 Plasma SUS Board Question

Also you may still have a bad component on the Zsustain. Sometimes when the IPMs go bad there is a diode or mosfet that also goes with it. I can't remember at the moment the position on the board but if I can find it I will let you know.

[TECHMECH]

Re: Toshiaba 50HP66 Plasma SUS Board Question

Hello, the Vs problem was fixed. It is stable at 196 where it should be, I have gotten the set to stay on now but the problem is the clicking noise and the bad picture as describe in post #3.

[mbates14]

Re: Toshiaba 50HP66 Plasma SUS Board Question

Replace the Y-buffers. Make sure your voltages are correct before doing so.

ran into a 50HP66 that done just this. bad buffers. no Y-addressing.