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Equipment Repairs => LCD TV forum => Topic started by: Geoff S on July 02, 2011,05:14:07

Title: HELP!! Bush LT26MC1A
Post by: Geoff S on July 02, 2011,05:14:07

Any help would be appreciated on a BUsh LT26MC1A with a 715T2907-2 psu.

The set responds to remote or manual switch on IE The standby light switches from red to blue and that's it, no backlight no sound. I have to switch off at mains to get back to standby.

Upon inspection I found the 12v reg IC had failed. After extensive searching I obtained and fitted a new one which has got the 12v back up but the set behaves the same. I'm thinking eeprom corruption. Any thoughts? Customer is starting to get restless!!

Cheers

Title: Re: HELP!! Bush LT26MC1A
Post by: Turnip on July 02, 2011,12:42:46

Hi figuy,

Nothing but a piccy - what was the part number of the 12v reg - curious - Chris

Title: Re: HELP!! Bush LT26MC1A
Post by: jimca007 on July 03, 2011,09:51:19

looks very like one I've been working on came out an acer 26 inch found the two mosfets on the left hand side of the primary were faulty although not shorting which is unusual they weren't passing power either.... worth a stab takes 10 mins and a steady hand to change !

Title: Re: HELP!! Bush LT26MC1A
Post by: Geoff S on July 05, 2011,08:33:22

Quote from: Turnip on July 02, 2011,12:42:46

Hi figuy,

Nothing but a piccy - what was the part number of the 12v reg - curious - Chris

Hey Chris.
The IC ref is IC904 Type SI-8105QL

Title: Re: HELP!! Bush LT26MC1A
Post by: Geoff S on July 05, 2011,08:35:32

Quote from: jimca007 on July 03, 2011,09:51:19

looks very like one I've been working on came out an acer 26 inch found the two mosfets on the left hand side of the primary were faulty although not shorting which is unusual they weren't passing power either.... worth a stab takes 10 mins and a steady hand to change !

Thanks for this. I'll give them a look. Fingers crossed.
Cheers
Geoff

Title: Re: HELP!! Bush LT26MC1A
Post by: Geoff S on July 14, 2011,07:36:32

The mosfets check ok. I'm guessing the main pcb has a problem. I'll post cure if I find it!!

Title: Re: HELP!! Bush LT26MC1A
Post by: fix2003 on July 15, 2011,02:59:31

only seen 32" version need these doing
At switch on Red led goes green and a faint ticking noise from psu

            Shottky diode DM854 (MBRF1545CT) in PSU was S/C.

            Replaced ICM801S (F9222L) in PSU.

            Replaced capacitors CS802, CS803 and CM805.

            CM808 (22nF/1250V) on power supply board.

Title: Re: HELP!! Bush LT26MC1A
Post by: Geoff S on July 19, 2011,09:47:12

Thanks for the info. Looks like they use a different PSU in the 32". None of the ref No's appear on this board.

Cheers all the same.
Geoff