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KevinWhiteJA
KevinWhiteJA, Technician
Category: TV
Satisfied Customers: 1010
Experience:  10+ years experience in electronics
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My LG 27LZ55 briefly displays a picture when the set is switched

Customer Question

My LG 27LZ55 briefly displays a picture when the set is switched but then a blank screen. The sound is fine, any thoughts?
Submitted: 2 years ago.
Category: TV
Expert:  KevinWhiteJA replied 2 years ago.
Customer:

Hi, welcome to Just answer

Customer:

How old is this unit ?

JACUSTOMER-gpusvvml- :

about 7 years

Customer:

OK, do you hear any different sound when it comes up with blank screen ?

JACUSTOMER-gpusvvml- :

no, sound quality seems to be the same

Customer:

OK and what all is connected to the TV ?

JACUSTOMER-gpusvvml- :

A DVD player, temporary connection to computer and Freeview TV box

Customer:

OK, the sound works perfectly fine even when you change the inputs ?

JACUSTOMER-gpusvvml- :

yes all three inputs provide good sound, I know that there is a picture there because it flashes briefly when I switch the set on and off. The TV worked fine until a day or so ago and then developed this fault i.e. there have been no movements of the set or the associated connections.

Customer:

OK, and do any of the lights blink after the picture goes off ?

JACUSTOMER-gpusvvml- :

sorry which lights? the led power indicator is the only visible light and that remins a constnt red or green as to whether on stand by or on.

Customer:

OK, thanks ....

Customer:

please unplug it for few minutes, plug it back after 2-3 minutes..then grab a flash light and shine it on the screen when the picture goes off, closely check and please let me know if you are able to see really dark picture or there is no picture whatsoever ?

JACUSTOMER-gpusvvml- :

OK give me a few minutes

Customer:

sure

JACUSTOMER-gpusvvml- :

the picture appears briefly and then it's a blank screen i.e. I cannot see a darkened picure

Customer:

the problem is most likely with the main board, as the sound is working fine I will also check the inverter board before checking the main board for any damaged components ... if the inverter board is replaced it will cost around £60 + labor

Customer:

and if it the problem is with the main board it will cost around £90 + labor

Customer:

if you are willing to repair this yourself then with the unit unplugged, remove the back off and check main board, it is the one with input jacks

JACUSTOMER-gpusvvml- :

Are there any typical faults with the main/inverter boards?

JACUSTOMER-gpusvvml- :

which might cause these effects?

Customer:

usually the components on the main board goes bad which might cause these kind of problems

Customer:

are you willing to repair this yourself ?

JACUSTOMER-gpusvvml- :

yes I'm reasonably proficient, however without a wiring diagram it's difficult, hence my questions to you.

Customer:

OK, take the back off with the unit unplugged for a while, check the main board first for any damaged components...usually the caps on this goes bad after few years...as there was no darkened picture so the inverter board should be fine however, you can also check that closely...I believe nothing apart from these two boards will cause this problem

Customer:

If you have further questions I will be pleased to assist you – please use the REPLY link for further assistance..Please remember to RATE my answer Excellent or Good Service ...Thanks

JACUSTOMER-gpusvvml- :

Thanks, ***** ***** el caps tend to dry out particularly quickly and as there are few boards in these sets it's fairly predictable to assign this fault to the main board. I had hoped there would have been a few tips on where to focus on, e.g. elsewhere I understand that etching has been an issue with this design in particular socket joints. Over the next few days I will take a closer look.

Customer:

OK sure... please let me know how it goes

Customer:

If you have further questions I will be pleased to assist you – please use the REPLY link for further assistance..Please remember to RATE my answer Excellent or Good Service ...Thanks

Customer:

Please don't forget to leave a rating as that is the only way I receive credit for the assistance that I
have provided today...Thanks :)