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 Louie Your Own Question
Louie
Louie, Technician
Category: TV
Satisfied Customers: 2557
Experience:  25+ yrs. experience in the field and 5+ yrs. online, down to component level.
13948492
Type Your TV Question Here...
Louie is online now
A new question is answered every 9 seconds

37" LG LCD TV, power light flashes 20 times then stays. Back

Customer Question

Good evening - 37" LG LCD TV, power light flashes 20 times then stays green. Back light comes on but no video. Light used to flash 7 times and turn red - but after re-flowing the solder joints it has gone to the 20 then solid green.
Submitted: 1 year ago.
Category: TV
Customer: replied 1 year ago.
I've tested the voltages on the power supply - all are correct except for 6v on P202 - it reads 7.1v - Have not tested 3.4v as I do not know where to jumper P201 3.4v ON - Leaning towards the main board being the issue and not the power supply - unless the 7.1v is the issue.
Expert:  TV Tech1 replied 1 year ago.

all are correct except for 6v on P202 - it reads 7.1v - Have not tested 3.4v as I do not know where

That 6 volt supply is NORMAL, And you DO HAVE 3.4 Volts - the TV won't light the backlights if it was dead.

Since you do have backlights, the main board is powering up the power supply, so it's either the MAIN...or the TCON that's causing your problem. Even Techs can't measure that unless it's taken to shop and tested with an oscilloscope. I just bring both boards to the customer's home and try both.

Of course it's an OLDER TV, so I'd make sure both are available on Google

Customer: replied 1 year ago.
Well I decided to try the 5.00 fix before replacing the mainboard at 60.00 used from ebay. Two 3300uf caps on the power supply looked a little bulged as compared to the rest. I replaced them and all is working well now. Oddly - the power supply voltages did not change one bit - but the TV now turns on just fine. They must pass some sort of signal that the TV needs to turn on. My knowledgless theory anyway. Thank you.