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Equipment Repairs => LCD TV forum => Topic started by: Geoff S on August 03, 2011,12:22:43

Title: LG 42LF66 psu prob?
Post by: Geoff S on August 03, 2011,12:22:43

Can anyone enlighten me about a 42" LG?

The picture drops out and leaves a blank screen after a couple of mins. Back lights are on and sound is ok.

I found two bad caps in the psu. 2200uf and 3300uf both 10v

It won't respond to remote when pic goes.

I wonder about the tcon board but the not responding to remcon makes me think about the psu.

Help would be appreciated.

Cheers

Title: Re: LG 42LF66 psu prob?
Post by: Ohm Supplies on August 07, 2011,05:54:31

hifiguy.

What is the board number of the main board? If it has 2 plugs at the top L.H.C, are there several small brown inductors? if so, are they all brown or do they have a small square mark on them?

regards
Andy

Title: Re: LG 42LF66 psu prob?
Post by: michael first on August 08, 2011,06:15:27

hi hifiguy,
tv tony gave the answer to that problem a while ago and it worked.look for the posts of him.

Title: Re: LG 42LF66 psu prob?
Post by: Geoff S on August 10, 2011,11:51:00

Quote from: Ohm Supplies on August 07, 2011,05:54:31

hifiguy.

What is the board number of the main board? If it has 2 plugs at the top L.H.C, are there several small brown inductors? if so, are they all brown or do they have a small square mark on them?

regards
Andy

Hey Andy
The PCB No is LD/PD73/75A
There are no inductors fitted that I can see but there are blanks marked FL901 through 908 where I assume they would be.

Geoff

Title: Re: LG 42LF66 psu prob?
Post by: Ohm Supplies on August 11, 2011,12:26:26

Sorry Michael, I didn't realise Mr w had posted a cure for this fault.

Andy

Title: Re: LG 42LF66 psu prob?
Post by: Geoff S on August 11, 2011,15:59:43

Quote from: michael first on August 08, 2011,06:15:27

hi hifiguy,
tv tony gave the answer to that problem a while ago and it worked.look for the posts of him.

Cheers for this. I've looked for the post you've mentioned but can't find it.
Any search tips?

Geoff

Title: Re: LG 42LF66 psu prob?
Post by: tv tony on August 13, 2011,05:59:47

then here it is again, good luck



remove the ceratech filters on the main pcb and short across, they are 908,904,903,906,905,902, all are situated near the connector from the psu, p900. the chokes are preceded by fl. this is official from lg
tony walker

Title: Re: LG 42LF66 psu prob?
Post by: Geoff S on August 13, 2011,06:09:22

Quote from: tv tony on August 13, 2011,05:59:47

then here it is again, good luck



remove the ceratech filters on the main pcb and short across, they are 908,904,903,906,905,902, all are situated near the connector from the psu, p900. the chokes are preceded by fl. this is official from lg
tony walker

Thanks a lot Tony.
Really appreciated.
Going to get on it later today and hopefully get some success.

Geoff

Title: Re: LG 42LF66 psu prob?
Post by: Geoff S on August 13, 2011,07:48:19

Quote from: tv tony on August 13, 2011,05:59:47

then here it is again, good luck



remove the ceratech filters on the main pcb and short across, they are 908,904,903,906,905,902, all are situated near the connector from the psu, p900. the chokes are preceded by fl. this is official from lg
tony walker

Hi Tony
I've checked the board and the filters aren't fitted and never have been. The connections are there.
I wonder if this is a mod'd board.
Would soldering the links be recommended under these circumstances?
There is one fitted at FL901 which isn't mentioned in your ref No's
Interestingly the connections all read ok continuity wise.

 :17:
Cheers
Geoff

Title: Re: LG 42LF66 psu prob?
Post by: tv tony on August 13, 2011,09:47:48

hello geoff,
                     once lg knew these ceratech filters were no good they stopped using them, sets after a certain serial number were modded at the factory, im on the lg site now looking for possible reasons for your problem, i will report back
tony walker
ps                      the lf was full hd, but ill have a look