Lg55ls4500 no power

[TvNewb23]

Hi all, long time lurker. I've got this tv and the tv will not power on. There is no standby light on the tv and I'm not sure where to start. I've done a few tv repairs. Led change out and replaced a few bad caps on a couple but this one has no obvious signs and looking to learn some troubleshooting on this one. I did test the unit for 3.5 v and it has that. Didn't see a printed stby so I'm not clear if I tested the standby power. I attached a few pics for reference

[budm]

Re: Lg55ls4500 no power

https://www.badcaps.net/forum/attach...9&d=1503527243

You need to report the DCV reading of all 24 pins on that connector.
The exposed pins you are seeing on the top side of the board are the ODD number pin, pin 1 is on the right most where the black dot is and that pin is 'PWR-ON'. The even number pin you will have to probe from the back side of the connector where the wires go into the connector.
You MUST put down the pin name and follow by the DCV reading of each pin.

[TvNewb23]

Re: Lg55ls4500 no power

Bud,
What a quick reply, rather than me making a chart for all 24 pins

All voltages are 0vdc other than pins 9-12 which have the 3.5vdc as marked

[budm]

Re: Lg55ls4500 no power

So other pins have no reaction when the power switch is activated? If that is the case then your main board is dead, it is not sending any command signals at all. Something is locking out the board.
We need to see the whole back side of the TV showing all the boards and how they are connected together.

[TvNewb23]

Re: Lg55ls4500 no power

Bud, You are correct, no reaction from power button, or remote It is also worth mentioning this set does not have physical buttons for power, volume etc. just touch. .. pics of overall set attached.

Thanks again.

[maxvalutech]

Re: Lg55ls4500 no power

Surely with no standby light you check voltage on main cap then if OK force PSU on for correct voltages being produced and if OK then to main . But no standby light = ????

[TvNewb23]

Re: Lg55ls4500 no power

So I jumped the 3.5v to pwr on. All voltages on that connector matched what was printed.

[aaronwt6]

Re: Lg55ls4500 no power

That would almost certainly point to a main board issue then. Replacing the main board should take care of the problem.

[TvNewb23]

Re: Lg55ls4500 no power

Update, replaced main board and tv working great.

[budm]

Re: Lg55ls4500 no power

Thanks for the follow-up on the repair.