Wanted LG 37LH5000-ZB screen problem!

[netdent]

from switch on black screen with some twitchy lines at very top

after a few mins some white showing in patches with vertical lines

then 5 to 10 mins later white screen with lines, top centimetre of screen showing image

Almost hour later full image that freezes followed later by nice minty picture!!

advice help welcome

voltages all good at psu but noticed at t-con fuse getting 11.80 changed smoothing cap on 12v rail still the same!

thanks Ronnie

[tom66]

Re: Wanted LG 37LH5000-ZB screen problem!

LG panel?
Tab bonds.

[netdent]

Re: Wanted LG 37LH5000-ZB screen problem!

LG panel?
Tab bonds.

I considered that Tom but it's not like the one's I have seen! flexing and poking in the area makes no diffrence likewise when picture is perfect no prodding or poking can make it go bad again

cheers Ronnie

[tom66]

Re: Wanted LG 37LH5000-ZB screen problem!

I would see if a t-con is cheap. If it is I would swap it. But I suspect the panel.

[netdent]

Re: Wanted LG 37LH5000-ZB screen problem!

I would see if a t-con is cheap. If it is I would swap it. But I suspect the panel.

that's my worry too, t-con is £30 main board near £40, dilema!! I have a hunch it is not the screen but am often wrong lol

Ronnie

[mu2]

Re: Wanted LG 37LH5000-ZB screen problem!

Hi,

I have a Vizio VL370M with the same or very similar problem.
Mine has a bad tab bond. Perhaps they use the same panel?
Try heating the upper left of the screen with a hair dryer and see if the time to a full good image decreases. My bad bond is on the upper left.
I was able to get a dramatic decrease in the time after heating.
I tried a couple different types of material to put pressure on the tab bond and could not find a reliable fix.
Good luck.

Mike

[netdent]

Re: Wanted LG 37LH5000-ZB screen problem!

Hi,

I have a Vizio VL370M with the same or very similar problem.
Mine has a bad tab bond. Perhaps they use the same panel?
Try heating the upper left of the screen with a hair dryer and see if the time to a full good image decreases. My bad bond is on the upper left.
I was able to get a dramatic decrease in the time after heating.
I tried a couple different types of material to put pressure on the tab bond and could not find a reliable fix.
Good luck.

Mike

thanks Mike, I was at it with the hair drier it made no diffrence what panel is in yours?

Ronnie

[mu2]

Re: Wanted LG 37LH5000-ZB screen problem!

Ronnie,

I put the set back together and didn't write down the panel number, Sorry.
I seem to recall that if the set was horizontal (with the panel facing up) - the on time seemed to decrease.
I assumed that it was due to more heat being trapped in that area and not escaping through the vents in the top if the set was vertical.
If you have the metal trim removed from the panel and the set horizontal - try the hair dryer again on the upper left tab bond area. Mine seemed to be sensitive in the area where the ic is bonded on the flexible circuit board. This is between the panel and long narrow board that attaches to the t-con.

Mike

[netdent]

Re: Wanted LG 37LH5000-ZB screen problem!

Hi Mike,

Yes I stripped the screen and applied heat and behold picture within mins!

Only heat worked tho not touching or pushing made it work, so yes another bad panel, not good! at least I never spent money on boards

thanks to you and Tom for input

cheers Ronnie

[tom66]

Re: Wanted LG 37LH5000-ZB screen problem!

Sometimes the bonding on the edge of the LCD itself can fail, instead of on the driver board.

[netdent]

Re: Wanted LG 37LH5000-ZB screen problem!

Sometimes the bonding on the edge of the LCD itself can fail, instead of on the driver board.

Thanks Tom, good to know these things before wasting £££

Ronnie

[mu2]

Re: Wanted LG 37LH5000-ZB screen problem!

Ronnie,

Glad to help. This forum has helped me a lot in solving problems and I like to give back if I can provide good information.
If you find a way to solve the problem please post - it might resurrect my Vizio.
When I have a bit of time I intend to try pieces of a silicone backing sheet in that area to provide pressure. Maybe the fault isn't on the actual bonding of the flexible circuit board to the panel or driver board but the connections of the IC to the flexible board?

Mike

[mu2]

Re: Wanted LG 37LH5000-ZB screen problem!

Ronnie,

Had a typo in my last post. I meant silicone "baking" sheet instead of "backing" sheet.
The material should easily withstand the temperatures.

Mike

[netdent]

Re: Wanted LG 37LH5000-ZB screen problem!

Ronnie,

Had a typo in my last post. I meant silicone "baking" sheet instead of "backing" sheet.
The material should easily withstand the temperatures.

Mike

Hi Mike,

Yes I spent some time with that silicone stuff but no results, I have managed it in the past on an lg 42 lcd and it worked well but I have given up on this one

thanks Ronnie