LG 60PX950UA Main board issue

[Mustangflyer]

Through the help of the forum, I believe I have a bad main board. Back story.
TV turns on, panel primes, but has no video. Sound works fine along with remote controls.
I jumped the CTRL board at R51 and R52, and unplugged the ribbon cable going to the main board and was able to get the Test patterns to display.

Scowering the internet ive been unable to find the board in stock anywhere. I have found 2 places that say they can be repaired (unless the cant then they offer a refund).

Im wondering if there is anyway to figure what has failed myself, save some money and learn a few things in the process.

The tv was given to me from a friend, who had replaced the Y-sus and the lower Y Buffer and had given up on it.

Any input would be appreciated! Thank you guys!

Dan

[martino]

Re: LG 60PX950UA Main board issue

BGA chip under that large heat sink? Knowing its a LG prob a reflow of that chip solves it.
Also those barrel shaped caps can be suspect although I'd think you would get more of a intermittent fault.

[Mustangflyer]

Re: LG 60PX950UA Main board issue

So should I pop off the heat sync and solder the joints together? Oven method?
Heat gun?

[Mustangflyer]

Re: LG 60PX950UA Main board issue

Is there a way to tell if the small board between the ctrl board and the main board is at fault? Or does doing the test pattern rule out that small board?

[chrismurphy]

Re: LG 60PX950UA Main board issue

So should I pop off the heat sync and solder the joints together? Oven method?
Heat gun?

Heat up the heatsink to make it easier to remove
wipe the BGA chip surface with some smear of oil or Teflon spray
Place a small c shaped piece of solder on the BGA chip
Heat with a heat gun slowly until the solder melts
works every time I have done this ,this assumes its the BGA chip issue and not something else

[mmartell]

Re: LG 60PX950UA Main board issue

Heat the chip thoroughly with a hair dryer then test the set for video to make sure this is your problem.

[Mustangflyer]

Re: LG 60PX950UA Main board issue

Well heating up the chip worked! Tv is working great and looks way better than my old 50inch! Thanks guys so much. Couldn't have done it without you

[dick_barton]

Re: LG 60PX950UA Main board issue

It's not a guaranteed permanent fix but unless you know anyone who could reball the BGA chip it's really all you can do.