Samsung LE32M87BD No contrast

[andyanz]

Hi, I see a lot of this type of tv but never had this fault. Set works but there is no contrast. Menu bars move left to right but no change. Done usual eeprom reset and fitted new eeprom. still the same. Psu caps etc all ok. Any ideas. Im thinking main board ?

[budm]

Re: Samsung LE32M87BD No contrast

post a screen shot so we can see what the picture looks like.
More likely to have AS15 GAMMA IC (U402) problem in the T-CON board.
http://www.shopjimmy.com/media/catal...5531T03112.jpg

http://www.shopjimmy.com/catalogsear...sung+LE32M87BD

[andyanz]

Re: Samsung LE32M87BD No contrast

. hi thanks for reply. I hope i have uploaded pics ok as first time in trying. Contrast n brightness controls move but have no effect. bright screen with no depth. When pressing menus the last one can still be seen before fading. t con is. T315XW02 v6. Many thanks in advance

[tom66]

Re: Samsung LE32M87BD No contrast

Looks like a gamma IC fault. Post a picture of the T-con board.

[andyanz]

Re: Samsung LE32M87BD No contrast

[tom66]

Re: Samsung LE32M87BD No contrast

Please take a picture in focus, we need to see the small text and small components on the board. In particular along the bottom of the board.

[stj]

Re: Samsung LE32M87BD No contrast

do these AS15 chips run hot?
just wondering why they all die.

[tom66]

Re: Samsung LE32M87BD No contrast

They usually do not run above about 35°C (barely warm to the touch), and since the output fault affects multiple channels, it seems like it is some kind of internal bias or compensation circuit gone wrong.

[budm]

Re: Samsung LE32M87BD No contrast

Tom, This picture may help. Provided by SJ.

[tom66]

Re: Samsung LE32M87BD No contrast

Yes so andyanz will need to test the VGAMA points from 1 to 22 (some missing) on the right hand side of the board, just under right most ribbon connector.

[andyanz]

Re: Samsung LE32M87BD No contrast

Thanks guys you have been fantastic. Ive ordered a replacement t con today. will post the results when fitted. Many thanks again

[tom66]

Re: Samsung LE32M87BD No contrast

You did not test the gamma voltages VGAMA to see if the original T-con is actually bad...?

[andyanz]

Re: Samsung LE32M87BD No contrast

Took a gamble as top ribbons are difficult to get too as hidden under top frame.

[andyanz]

Re: Samsung LE32M87BD No contrast

Fiited another t con. all working fine now, many thanks for everyones help

[budm]

Re: Samsung LE32M87BD No contrast

Thanks for the follow-up.