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Shahid
Shahid, Technician
Category: TV
Satisfied Customers: 9465
Experience:  I have been repairing electronic gear since 1993 as a qualified Sony tech
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My LG 50PT350-UD won't turn on. When I press the power

Customer Question

My LG 50PT350-UD won't turn on. When I press the power button I hear several clicks, the red power light goes out, then some more clicks and then the red power light comes back on. I have replaced the power supply board but still the same problem. What do I do now?
Submitted: 1 year ago.
Category: TV
Expert:  Shahid replied 1 year ago.

Hello, I'm Shahid and will be happy to assist you. I need additional info to troubleshoot the issue.

- Does screen glow for a while when power On the TV?

- Do you get program sound from TV speakers?

Thanks.

Customer: replied 1 year ago.
Hi Shahid,The screen does not glow for a while when the TV is powered on.
There is no sound coming from the TV speakers.When I turn on the TV, it seems like there's not enough power to start it up, the power then fades and then the tv resets to an "off" state.Thanks,
Chris
Expert:  Shahid replied 1 year ago.

Hi Chris,

Thanks for the info. This kind of problem mostly occurs due to failure of scan boards in TV known as y-sus and z-sus located on either sides of rear of panel. It needs further troubleshooting with multimeter to determine which board is not working to get it replaced. Please reply back if you have multimeter and can check high volts on circuit boards inside TV to troubleshoot it if you wish to repair the TV yourself and if you are not comfortable working on it yourself then you may please use following link to get list of TV repair shops in area which will help to get repair quote...
http://www.tvrepairpros.com/
I'm sorry there is no easy or quick fix for this problem and it is definitely hardware failure that needs defective board replacement to resolve the issue. I trust my input will help you out to make decision about this TV repair or invest that money on new replacement TV. Please feel free to respond if you have any additional questions.
A positive rating to answer would be greatly appreciated, please click on 5 star on this page then click submit/finish button so I can get credit on website for my work.
Regards,
Shahid.

Customer: replied 1 year ago.
Hi Shahid,Your conclusion that it's the y-sus and z-sus that are causing the problem doesn't make sense to me. It appears to be a power problem. Other sites have indicated that these types of issues relate to either the power board or the main board but I'm not sure what they are referring to by the main board. Are there some tests I can do to determine where the fault is? I have a multimeter.
Expert:  Shahid replied 1 year ago.

I'll try to explain it, if screen shows any light/ glow even for a second on start up that means scan boards are working and next suspected thing would be main board, one that has all video inputs, main controller/ processor chip that controls all the functions of TV. Scan boards failure is most common in plasma TVs and TV mostly wont turn On/ power button doesn't work in case of main board failure or you will get noisy image or lines or bars etc on screen.

I hope these info will help, please feel free to respond if you have any additional questions.
A positive rating to answer would be greatly appreciated, please click on 5 star on this page then click submit/finish button so I can get credit on website for my work.
Regards,
Shahid.

Customer: replied 1 year ago.
Hi Shahid,Can you tell me what to check with my multimeter to diagnose where the problem is occuring?Thanks,
Chris
Expert:  Shahid replied 1 year ago.

Chris, need to check Vs and Va volts output P811 on power supply board that goes to scan boards, if volts appear for a while then unplug connector and again check Vs and Va volts on power board that would stay longer and it indicates shorted scan board, probably ysus board located on left side of rear of panel.

Thanks.