How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask Shahid Your Own Question
Shahid
Shahid, Technician
Category: TV
Satisfied Customers: 10485
Experience:  I have been repairing electronic gear since 1993 as a qualified Sony tech
33243543
Type Your TV Question Here...
Shahid is online now
A new question is answered every 9 seconds

I have a vizio lc420 tv. Had a thunderstorm with lightning.

This answer was rated:

I have a vizio lc420 tv. Had a thunderstorm with lightning. The tv was unplugged from power, but I forgot to unplug it from phone/dsl jack. Modem had to be replaced, tv won't turn on. Looks like the power fuse in the tv is okay, checked it with a meter with it still in the holder, I have continuity. Nothing obvious in the area where the Ethernet cord plugs in.
Hello, my name isXXXXX be happy to assist you,
Please allow me to ask you a few questions about your TV so that we can troubleshoot the issue.

- Can you please recheck and provide complete model number written on back of TV?

- Do you get 5V output on power supply board?

Thanks.
Customer: replied 3 years ago.

lc420wuh. Where on ps board do I check 5v?


 

Thanks Brian for the reply.

There is connector on power board and wire harness goes from that connector to main board of TV.
Please check 5.1VSB on that connector as volts reading is stamped there as well.

What volts reading appears on meter?
Customer: replied 3 years ago.

I'm not reading any voltage with one lead touching a ground on the connector and any of them marked 5v. This is the same board where power comes in, correct?

Yes, that is the power supply board where AC cord plugs in.

Do you get any reading at any pin of that output connector?

Customer: replied 3 years ago.


Sorry, I had power plugged in but power strip turned off. I read 5 + something volts there

OK, so standby volts (5V) appears.

- Does power indicator light on TV turn On when power cord plugs in?
Customer: replied 3 years ago.

I do not see any lights


 

Sorry to hear that.
Brain, it seems main processor chip has become defective because of thunderstorm with lightning and we need to replace main board of TV to resolve the problem. Sorry for bad news.

5V standby supply is to turn On main processor chip that controls rest of TV functions like turning main power supply section when press power button and picture & sound controls etc.

Please check following site link that would have required replacement board...

http://www.shopjimmy.com/catalogsearch/result/?q=lc420wuh

Please make sure replacement main board is exactly same identical board and has same part number as the board in your TV. You may please search/ google required main board as per part number written on it for better price.

I trust my input will help you out. Please feel free to respond if you have any additional questions.
A positive rating to answer would be greatly appreciated!

Regards,
Shahid.



Customer: replied 3 years ago.


I'm not surprised. Nothing good happens with a lightning strike. Thanks

Brian,

I wish I had better news about TV but symptoms pointing towards main board problem.

Please feel free to respond if you have any additional questions.
A positive rating to answer would be greatly appreciated!

Regards,
Shahid.
Shahid and other TV Specialists are ready to help you
Customer: replied 3 years ago.

Hello, I have replaced the main board and the tv turns on, but now I have a black screen. The light on the bottom right corner is on, there is no sound

Hello Brian,

- Did you get identical version main board as per part number written on old board?

Thanks.
Customer: replied 3 years ago.

Yes.


Does screen show up faint glow when TV turned On? faint glow will tell us that screen has back light.

Also, please recheck all connectors are plugged in securely that were removed during main board replacement.

Thanks.
Customer: replied 3 years ago.

okay, rechecked connectors and found one of the two belt type connectors was not connected properly. I reattached both of the belt connectors, but the top one is the one that looked wrong. Reattached and now tv comes on, with sound. But the left side of the screen is a white box. The right side looks as though the picture is too big for the screen. Any text on the screen is backward and the picture is fuzzy.


It seems main board is mismatched with the display panel in your TV or we are still having some connector issue especially the one going to display panel.
Is it possible if you can upload / provide a good picture of rear of TV to see how every thing is hooked?
You may please upload picture at any free photo sharing website and post here the link to view it.

Thanks.
Customer: replied 3 years ago.

TV is FIXED! I rechecked the connections and one of the ribbon connectors was just a hair off. Reseated and it has been working fine. Those ribbon connectors are difficult to seat properly.Thank you very much for your help.

Excellent Brian, glad to know problem is resolved and TV is back in business.

Please feel free to respond if you have any additional questions.

Regards,
Shahid.