Vizio JV50P HDTV10A - YSUS problem

[ChrisV]

Working through a problem with this TV. I really need some guidance.

The voltages from the power supply are good to the YSUS and ZSUS cards.

When both buffer boards on the YSUS are in place, the voltage drops out at the VSC and -Vy test points. both YSUS and ZSUS heat sinks remain cold.

If I remove the upper YSUS buffer board, heat sinks on both cards begin to warm up and the voltage to the 2 test points returns but I still have no signs of picture or backlight.

My question is...What would cause the voltage to drop out when the upper buffer is in place? I've already replaced the upper buffer and YSUS card and the symptoms remain the same. I've read in a few of the threads, that these buffer cards are not prone to failure.

Any help is appreciated

[ChrisV]

Re: Vizio JV50P HDTV10A - YSUS problem

Is it possible that the used YSUS card that I installed is bad?
The symptoms are the same with both cards. Makes me wonder if something else is causing power to drop.
Any ideas??

[PlasmaRon]

Re: Vizio JV50P HDTV10A - YSUS problem

I have a P50HDTV10A that I've been working on. Do you know if it's roughly the same as the JV50?? I'm near Portland. How far north of PDX are you?

[ChrisV]

Re: Vizio JV50P HDTV10A - YSUS problem

Hi Ron. This is the first Plasma that I've ever worked on. I'm learning as I go. I don't have enough experience to tell you if the two TVs are the same. Looking at pictures of the P50HDTV10A in another thread, the boards inside the TV are not identical.
My feeling is that the general concepts for troubleshooting are probably the same.

I live in Ridgefield near the fairgrounds exit.

[PlasmaRon]

Re: Vizio JV50P HDTV10A - YSUS problem

Chris,
Did you ever get your set working? I made some progress on mine. I ended up buying one that was working so that I could do a board swap 'till I found out what board was actually bad and it turns out that the YSUS was bad. I'm looking into repairing that down to component level but just wondered what you've found.

[ChrisV]

Re: Vizio JV50P HDTV10A - YSUS problem

Ron,
Yes, the TV is working perfectly. The small ribbon cables that plug into the buffer boards weren't fully seated into position. After getting them fully seated, the set started right up. In all, I fixed the power supply and replaced the Y-sus and buffer boards.
Coincidentally, I just bought the same TV as yours on Craigslist for $20 a couple of days ago. I just repaired the power supply on it and am trouble shooting the Y-sustain. Please keep me posted on your progress.

[PlasmaRon]

Re: Vizio JV50P HDTV10A - YSUS problem

Chris.. I picked up a 20A and found that the difference is in the Tuner/input board at the bottom. The configuration is a bit different between the two. Also the control board (the small rectangular one) is different and apparently not compatible. The PS's are interchangable. I think the Ysus is the same and the Zsus is close (one connector in the center is not stuffed on the PCB). I see you're not far away. Perhaps we'll have a chance to meet up sometime and exchange boards/knowledge! I've got a number of Panasonic sets working in the past.

[PlasmaRon]

Re: Vizio JV50P HDTV10A - YSUS problem

Chris,
Seems that the DTV board goes out when the caps on the supply finally take out the set completely. Both the sets I was working on had this problem in addition to the Ysus/buffer board issue. Not sure what goes out on the DTV card either. I have another 10A set that was supposed to be a working set but get no setup menu when I select DTV. Very odd