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hongkongpom
hongkongpom, Cable TV Installer
Category: TV
Satisfied Customers: 1269
Experience:  State Of Hawaii Certified Cable TV installer
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I have a 50" lg plasma, the tv will come on and play fine 15

Customer Question

Customer: I have a 50" lg plasma, the tv will come on and play fine for about 15 min then the screen goes black and sound still works. If you shut it off for a min it will come back on but it takes less time for it to go black again. while running and while black all the voltages going to the y and z sustain boards are good. but I dont know how to test what is coming out of them is good or not. while running the z sustain votages going to the plasma bounces up and down, once it goes black every pin reads 16.7 volts
JA: Thanks. Can you give me any more details about your issue?
Customer: I have a 50" lg plasma, the tv will come on and play fine for about 15 min then the screen goes black and sound still works. If you shut it off for a min it will come back on but it takes less time for it to go black again. while running and while black all the voltages going to the y and z sustain boards are good. but I dont know how to test what is coming out of them is good or not. while running the z sustain votages going to the plasma bounces up and down, once it goes black every pin reads 16.7 volts
JA: OK got it. Last thing — TV Technicians generally expect a deposit of about $18 to help with your type of question (you only pay if satisfied). Now I'm going to take you to a page to place a secure deposit with JustAnswer. Don't worry, this chat is saved. After that, we will finish helping you.
Submitted: 10 months ago.
Category: TV
Expert:  Anthony_Infotech replied 10 months ago.

Hello

Welcome

When it goes black if you press the menu button of the sets own remote control does the menu come up please?

What voltages where these?the Vs and VA?

Anthony

Customer: replied 10 months ago.
No, the menu doe not pull up. Yes Vs and VA are good going in both while playing and when screen goes black. The voltage going out of the ZSUS into the ribbon cables going to the panel, jumps up and down while playing and then once it goes black they all read 16.7V.
Expert:  Anthony_Infotech replied 10 months ago.

sorry i have to leave this please await another tech

Expert:  hongkongpom replied 10 months ago.

Hello please tell us what the model number is?

Expert:  hongkongpom replied 10 months ago.

In a dark room if you turn on the TV do you see the panel "Prime" ie show any lighting up please?

Customer: replied 10 months ago.
Model# *****
Lights up fine at 1st but when screen goes black there is no light coming from screen at all
Expert:  hongkongpom replied 10 months ago.

Thank you. Your problem is either with the X or Y sustain boards however I would change out the Y sustain board first.

Please get the Y sustain board number from your board in the TV and go to www.shopjimmy.com to order a replacement.

​Let me know how you go.

Customer: replied 10 months ago.
I had already ordered the y-sustain board as a guess. I just put the new one in, now when I turn it on it primes for about one sec and then goes black, where before it would play for 10min or so before going black
Expert:  hongkongpom replied 10 months ago.

Hello where did you order the board from please?

If the board is ok then you will need to replace the X-sustain board

Expert:  hongkongpom replied 10 months ago.

There is also the logic board that takes the signal from the main board and passes it to the sustain boards

Customer: replied 10 months ago.
Yea I can swap parts till I find it, but I was wanting to find out what and how to test so I dont have to keep trying different stuff.
Customer: replied 10 months ago.
oh and I ordered the part from encompassparts.com. its new
Expert:  hongkongpom replied 10 months ago.

It's normally a good idea to swap out both sustain boards. There are the two upper & lower buffer boards fed from the y-sustain but those symptoms are normally horizontal lines.

​If you feel the heat sinks of the sustain boards are they warm to the touch and not cold or very hot please?