LG 42PG20D Plasma freezing up

[Matk20]

Hi All,

Hopefully you can help, my Plasma keeps freezing quickly after turning on.

Everything seems ok for the first 30 seconds - 3 minutes before the TV stops responding and picture freezes. TV LED is flashing showing response from remote control but nothing happens. Any moving items on screen will freeze. All on screen menus function normally and image is fine before freezing.

I have noticed if I turn the TV on without any inputs connected and it seems ok, it would freeze immediately after reconnecting an antenna.

TV turns itself to standby after being frozen for a few minutes.


Im yet to test the TV with a component other than a tuner to see what happens with sound during freezing.


Anyone have any ideas of advice that could help?

Thanks

[tom66]

Re: LG 42PG20D Plasma freezing up

Can you post some pictures of the chassis layout?

[Matk20]

Re: LG 42PG20D Plasma freezing up

Photo attached shows chassis layout (I hope, posting from my phone)

[tom66]

Re: LG 42PG20D Plasma freezing up

The menus are completely navigable when it freezes?
If you select another source or change over-the-air TV channel, does the picture "defrost" (unfreeze) then freeze again?

[Matk20]

Re: LG 42PG20D Plasma freezing up

Sorry, menus are fine before freezing, after freezing I get nothing happen from the remote or buttons on tv (beside LED flashing o recognise remote control button being pressed) and obviously the picture is frozen.

[Matk20]

Re: LG 42PG20D Plasma freezing up

And no ability to change channel or input once frozen, only option is to turn off at power.

[tom66]

Re: LG 42PG20D Plasma freezing up

OK, on the left of the TV, the large board with heatsinks is the Y-SUSTAIN (connected to Y-BUFFER), and the smaller board on the right is the Z-SUSTAIN.

In the middle of this you've got the power supply (orange) and below it, you've got the control board. Can you get me a photo of the control board? I need to be able to see the points marked "EXT AUTO GEN", if they are present.

[Matk20]

Re: LG 42PG20D Plasma freezing up

This is the best photo I have at the moment of those 2 boards. I will take another photo next time I'm at home. What are your thoughts on the problem so far?

[tom66]

Re: LG 42PG20D Plasma freezing up

You can try jumpering EXT AUTO GEN with a 100 to 470 ohm resistor (if you do not have one places like Jaycar sell them.) This will put the panel into a test mode, showing patterns one after one. If it does not freeze, then we know the problem is with the main board, if it does freeze then it is a control board issue. At which point, you can use freeze spray or a hair dryer to locate any thermally sensitive parts, or you can replace the entire board.

[Matk20]

Re: LG 42PG20D Plasma freezing up

Awesome! I'll give that a shot tonight, I'll let you know the result.

[tom66]

Re: LG 42PG20D Plasma freezing up

Had a look at ShopJimmy and looks like EXT AUTO GEN is under that metal plate for the floor/table stand.

[Matk20]

Re: LG 42PG20D Plasma freezing up

Test patterns work perfectly and have been cycling through now for over 5 minutes.

So its the main board?

[tom66]

Re: LG 42PG20D Plasma freezing up

Yep. So if the problem happens after about 3 minutes you need to try and lengthen it. Begin by targeting the large "ST" processor with freeze spray. If it lasts much longer, then it probably has a bad BGA joint (like Xbox 360 and PS3 RROD/YLOD.) If you don't have freeze spray you can try heating up parts and see if the problem occurs quicker but due to how quickly it occurs it might be difficult to find the faulty part.

Or you can swap the whole board. Remember you can only use 42" board in 42" 720p PDP.

[Matk20]

Re: LG 42PG20D Plasma freezing up

So could it be an issue if the main board is labelled 60PG30UD? Because I assume that relates to a the 60 inch plasma model 60PG30?

I actually don't know much about the history of this TV, is it possible it has a main board replaced previously with one that is not compatible? Or is this the correct board?

[tom66]

Re: LG 42PG20D Plasma freezing up

Problem with the main board for the 42" is the panel is 1024x768 (widescreen, with wide pixels.)

But the 50" and 60" are either 1366x768 (720p) or 1920x1080 (1080p.)

So the panel image will not fit and it will be cut off or it won't work at all.

So I doubt the board is incompatible, it's just faulty.

[Matk20]

Re: LG 42PG20D Plasma freezing up

Ok cool, if I was to replace the main board how would I go about finding a part? I can't seem to locate the same one as a replacement, is there a different/similar board I can use?

The board says:

60PG30UD-AA
EAX41533504 (0)
08.08.08
L.K.T.

[tom66]

Re: LG 42PG20D Plasma freezing up

Does seem like you got the wrong board, but I'm confused. It actually works fine for those minutes before it freezes?

[JonathanAnon]

Re: LG 42PG20D Plasma freezing up

If you don't have freeze spray you can try heating up parts and see if the problem occurs quicker but due to how quickly it occurs it might be difficult to find the faulty part..

I rigged up this with a bit of square tubing.



I attached two PC fans to it (powered by either a car battery or 12V supply from the TV's power board) and focus it on the different boards to track down thermal problems..

[hienton2]

Re: LG 42PG20D Plasma freezing up

Put a heatsink on top of BGA chip. It may help .Like heat sink on BGA of computer mother board.

[tom66]

Re: LG 42PG20D Plasma freezing up

That would have helped if they did that in the factory, but I'm afraid that the damage has probably already been done.