Lg 60pn6550 turns off on its own

[Malachi]

I just bought this about a month and a half ago.
Sometimes it turns itself off if I change the channel or turn the volume up or down.
Twice in 3 days now. Every time it's happened, I would unplug it a couple times then turn it back on using the remote or the power button on the set itself.

When it turned off today, I left it off as I was doing something else and after about 5 minutes, it turned itself back on.

Last week I ordered a power subtly board as it was cheap.
Does it sound like a power supply issues?

[awyatt2]

Re: Lg 60pn6550 turns off on its own

sounds like control or main board, try warning boards one at a time with a hairdryer and see if it helps. sometimes if it is a bad cap it will start. I would chec k the voltages going from the power to the main and see what happens either the power is dropping at the ps or the main is shutting it down. you will need to post good high res pics of the boards to see if anyone here sees anything.

[Malachi]

Re: Lg 60pn6550 turns off on its own

Thanks. I will try replacing the power supply when it comes first, since I've already ordered it.
When I have it open for that, I will take pictures.
I don't think it's overheating as the TV can be on for hours with no problems.

[Malachi]

Re: Lg 60pn6550 turns off on its own

I opened up the TV. The inside part numbers all match up with parts for a 60pn6500 but the sticker label on the back of the TV says 60pn6550.
For example, at parts jimmy, the main board for the 6550 has 2 sets of component plugs and vga ports.
My tv only has 1 set of components and no vga plugs.
Not sure which parts I should order.
By TV model or number on the old parts themselves.

[ReeceyBurger123]

Re: Lg 60pn6550 turns off on its own

Dont just throw boards at it ! Diagnose it properly first save yourself some money ! Try what was mentioned in post 2.

[Malachi]

Re: Lg 60pn6550 turns off on its own

I don't have a digital meter. The power supply board was only $18 and the control board is $12.
But now that I opened up the TV, I see the power supply board I ordered doesn't natch the one in my tv.
The one I ordered is for a 60pn6550 but the one in my tv is for the 60pn6500.
Would it work? Or should I return it?

[Malachi]

Re: Lg 60pn6550 turns off on its own

Here are pictures for the main and control boards.

[Malachi]

Re: Lg 60pn6550 turns off on its own

Control board.

[Malachi]

Re: Lg 60pn6550 turns off on its own

It was a faulty main board. I couldn't find one for my tv so I tried one from a 50pn6500 and it worked.

[ReeceyBurger123]

Re: Lg 60pn6550 turns off on its own

Sorry we couldn't help, didnt see the thread. Good work though.

[Malachi]

Re: Lg 60pn6550 turns off on its own

I forgot to update it. I replaced the board in January.

[junker_unit]

Re: Lg 60pn6550 turns off on its own

To anyone reading this who can't find a replacement main board, it might be possible to fix this problem without buying anything. I borrowed a trick from computer repair forums - it involves removing the problem circuit board and baking it in the oven to reflow the solder joints. Yes, that's right.

If the TV works fine for a little while but then suddenly powers off, it is most likely a heat problem. If the TV warms up and cools down many times over months or years, it can cause fractures in the solder joints that produce exactly this kind of problem. It works fine when cool, but after warming up the fractures expand and it fails again.

I fixed my LG TV by removing the main board and baking it in the oven at 375 for about 7 minutes. Put it on a baking sheet suspended on a few crumpled up balls of aluminum foil. Let it cool completely before placing it back in the TV. Don't go any longer than 7-8 minutes because you don't want to melt any of the plastic connectors. After 7 minutes there were no signs of melting or warping on my main board, so you should be safe at that temperature/time. Most solder melts at 360-370 degrees so a temp of 375 is necessary.

[shaneo902]

Re: Lg 60pn6550 turns off on its own

does this work? and wont cause any damage to the board i just bought a tv with this issue. the main board is the one wit the hdmi and rca inputs thanks

[tvtimmy]

Re: Lg 60pn6550 turns off on its own

Try running tbe test patterns first. Unplug the ldvs cable from the mainboard and put a jumper wire in the auto_gen holes on the logic control board. Plug tv back in. You should have the test patterns on screen.let it run untill it shuts down(if it doesn't mainboard has the problem). If it does shut down, you have a cracked solder joint somewhere under a board.

[vavrkok]

Re: Lg 60pn6550 turns off on its own

For me it was diode D400 (BAW56) on main AV board - near SPDIF above LDO. When heated it goes open circuit, after replacement TV is working fine again . Based on schematic it is something to do with CPU reset circuit.

[pansatdishman]

Re: Lg 60pn6550 turns off on its own

For me it was diode D400 (BAW56) on main AV board - near SPDIF above LDO. When heated it goes open circuit, after replacement TV is working fine again . Based on schematic it is something to do with CPU reset circuit.

What's the replacement for this diode and is there a link for where to buy it thanks

[vavrkok]

Re: Lg 60pn6550 turns off on its own

What's the replacement for this diode and is there a link for where to buy it thanks

You can buy this diode - BAW56 from some local store or online (it's also on aliexpress but quality can vary)

[R_J]

Re: Lg 60pn6550 turns off on its own

.