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42lv5400-ub no display but turns on.

Serge 125

Member
Hi all!!!

Ok my 42lv5400-ub just decided that it doesn't show any pictures and yes I have done the flashlight test and don't see any thing on screen as for sound I don't know. It was working just a few mins ago and now nothing. I did noticed that when I turn it on I get a red led then I get 2 white flashing BUT the thing is that I found out that the TV is on because I can turn it off and I get the normal white led that turns on and off when the tv shuts down. So I didn't get the chance to test anything it happened late last night but I did took the time to take the back off for later today after work to check things out. I will try my T-CON power test thing to see if my lcd works with red, green, blue and white screen appearing. Still I'm asking anyone here for any advice so when I get back from work to test some of your suggestions and yes I do have the repair manual for it too. I do have a meter and a LED back light tester too. So thanks for any advice!!!!

THANKS in advance

Serge
 

Nigel Goodwin

Super Moderator
Most Helpful Member
Presumably the two flashes is an error code?, and any 'decent' make tends to shut the screen down totally if there's an error condition detected - which could be why the torch trick doesn't work. There doesn't seem to be any list of error codes in the manual, but that is unfortunately fairly common.

A quick google finds mentions of reflowing the BGA chip on the main board, for a multitude of problems, usually by putting the entire board in an oven.
 

Serge 125

Member
Hey THANKS for the quick reply!!! Yeah I did have video problems with that chip about a year ago but if this is the problem again then it went to another level. I have my Quick 861 air station so I’ll give it a good heat up “again” but I know it’s just a temporary fix, reballing would be the best thing to do but don’t have the stencil to put soldering paste on it. So later I’ll give it a good heat up again and check and if it works I’ll be my 3rd time reflowing that chip. As for sound I couldn’t check because I can’t see the input menu on the screen but I’m confident that it works. Ok will let you know how it went. Again thank!!!☺️
 

Serge 125

Member
Hi all!!

Ok reflowed yesterday and all is well (again) but like I said reballing is the answer to this problem. When I had to reflow I hade video problems (pic) but this time the screen was black no backlight at all BUT when I did the T-CON screen test (modding the T-CON for this) and it didn't work so this was an indication that the backlight was in protective mode. Gee just a chip can cause many problems. BTW THANKS again for your help next time i'll know better!! ;-)
 

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