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Equipment Repairs => LCD TV forum => Topic started by: Jabboy on September 16, 2012,16:47:27

Title: 42LG3000 Turns on for a second...... HELP!
Post by: Jabboy on September 16, 2012,16:47:27

Hi,

I am still new to this forum and wa shoping some geniune here can help me diagnose the above unit?
As in subject, The TV turns on for a brief second and then goes off leaving the standby light on Blue as if it is still on.
No picture or sound is desplay.

Would anyone kindly guide me through this to diagnose it?
I have all the basic tools such as soldering iron, Multimeter etc and can diagnose basic parts.
any help would be much appreciated.

Regards

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: Turnip on September 18, 2012,13:08:11

Hi Jabboy,

Only have it on file as a smaller screen set, perhaps a panel list might help - revert to S/by might be just a PS caps jobby - Chris.

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: Jabboy on September 19, 2012,17:40:39

Hi There,

I was under the impression it is the AV Board, but Unfortunately it wasnt as already changed thi sbut same issue.

The Caps on PSU have not gone, howevr I have an ESR meter I can test these with before changing any.

any other ideas mate?

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: watteau on September 20, 2012,03:17:45

Hi,
There is a bulletin for a similar problem to yours.
It just requires removal of C108, ZD111, and ZD112, on the print side of the power-supply.
All are located to left/right at centre of PCB.
It's worth a try, and won't have any ill-effects.
Regards,
John.

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: Jabboy on September 20, 2012,04:49:48

Hi John,

Many thanks for your advice, I will look for this and can remove them.
Could you direct me to where this bulletin  is please?

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: watteau on September 20, 2012,05:32:51

Hi,
You'll need access to the LG service site for the complete bulletin.
The information I've supplied was found on another Forum,
Regards,
John.

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: dskservices on September 20, 2012,05:39:23

dont want to insult anybodys intelligence here but have you checked the psu caps, they're a problem in this model.

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: Jabboy on September 22, 2012,05:20:35

I will check Caps with an ESR Meter and se eif that helps.
Cheers

Title: Re: 42LG3000 Turns on for a second...... HELP!
Post by: Jabboy on September 25, 2012,06:02:20

Quote from: watteau on September 20, 2012,03:17:45

Hi,
There is a bulletin for a similar problem to yours.
It just requires removal of C108, ZD111, and ZD112, on the print side of the power-supply.
All are located to left/right at centre of PCB.
It's worth a try, and won't have any ill-effects.
Regards,
John.

Hi John,

Removed the above and still the same issue.
I have also checked most of the large caps with an ESR meter and they are good.
Not sure what else it could be as I have changed Inverters, AV Board and same thing happens. So it must be the PSU. Before I go ahead and order one, does anyone have any idea on what to check on this PSU please?