lg 50ps30 has blury/jumpy picture

[nwcs]

I am a little confused by this problem. I am presuming it is the main board but I can find no service manual on it so I am just guessing. All voltages are good and on the logic main there are two led's one stays solid the other blinks 3 short one long blink. The picture is the same on all inputs and even the menu. It is almost 3D in effect. Does anyone have any thoughts to what it might be.

[Alastair E]

Re: lg 50ps30 has blury/jumpy picture

Try shorting Auto-Gen pins 2-3 and disconnect LVDS, Then plug set in and fire up.

Is fault still present on the displayed test-patterns?

If so, fault is either Control-Board or Y-sus
--I'll bet its the y, aas I had one do much the same....

[ReeceyBurger123]

Re: lg 50ps30 has blury/jumpy picture

The motherboards on these have alot of issues with Bga solder failure. I would say do what Ali said if all good, then heat mobo with hair drier see if it improves.

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

which connector is the auto-gen?

[Alastair E]

Re: lg 50ps30 has blury/jumpy picture

I had two Y-SUS for these, One that missed every other 'line' of pixels, the other did this double-image jump.

I suspect one of the C451 buffer-chips, but didnt have any at the time, a third good Y cured the problem...
As Reecey says--Mains have their issues too--There's insufficient cooling for some of the bga chips which leads to the chips wearing out. RoHS lead-free crap strikes again.
BGA soldering it seems Isnt the full story--Its apparently the silicon to substrate interface of the chips that fails--reflow/ball is a temp cure, full cure is new chips....

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

I talked to the owner and he says he was watching tv and it happened all of a sudden so I would believe it is the BGA chip but still want to try jumping the pins of the auto-gen if I knew where that was.

[Alastair E]

Re: lg 50ps30 has blury/jumpy picture

BGA tend to show fault from cold--not while watching. like, Was working last night, but today it wont go!

I still think the Y TBH.....

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

OK, I buy that. What connector do I jumper to get the auto-gen to work?

[Alastair E]

Re: lg 50ps30 has blury/jumpy picture

Ive used 2-3, if that doesnt bring 'em up, try 1-2

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

Again which connector (plug number) do I unplug to jump?

[Alastair E]

Re: lg 50ps30 has blury/jumpy picture

Unplug the lvds from mainboard, then on auto-gen link the pins.....

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

I get to unplug the lvds cable but I am confused where the auto-gen plug is. I presume that one of the connectors to the main board needs to be unplugged and jumped but I still do not know which connector you are referring to.

[Alastair E]

Re: lg 50ps30 has blury/jumpy picture

Auto-gen is on control-board and marked--I can see it from here!!

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

I did not see that thanks. Do I jumper the two contacts under the word auto gen then?

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

Never mind I see where to jump. I need to look a little closer.

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

I finely got something. I got a solid red picture for a few seconds jumping pins 3 and 4. It was brief but a good solid picture.

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

jumping pins 1 2 I get a green screen then a red screen then a black screen with a red jumpy line on the bottom. It is kind of hard for me to do this and look at the same time since I do not have the tv stand.

[ReeceyBurger123]

Re: lg 50ps30 has blury/jumpy picture

I agree with Ali then Y main fault.

[nwcs]

Re: lg 50ps30 has blury/jumpy picture

I am finally able to position the tv and do a proper test by jumping pins 1 and 2. I now get the test pattern and there are jumpy red lines on the bottom of the r g b picture and all of the other patterns are jumpy.