Inverted Colouras on Samsung LE37M87BD

[Mikeyboy2007]

hi guys bought this telly form someone (as faulty) , plugged it in and all the colours are inverted, there was a buzzing coming from the tv and after i turned down contrast etc the buzzing went away. any ideas ? also went into service menu and changed DDR to Samsung.

[tom66]

Re: Inverted Colouras on Samsung LE37M87BD

Pic of fault?

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

hi Tom, attached picture, also there is a little ghosting on the picture too.

[tom66]

Re: Inverted Colouras on Samsung LE37M87BD

Could be GAMMA or LVDS/FORMAT fault. A natural image (a face is best due to the smooth gradients) can help narrow down the exact fault.

First check LVDS cable seated properly both ends, no corrosion on any pins, no bent pins.

If that passes enter service menu and check LVDS format option: there may be a few, JEIDA is one of them. Try each and see if picture gets better. Also check panel setitng is correct - AMLCD 37" for example is SAMSUNG 37" panel. Note down all settings before changing them.

Should those fail then a picture of the T-con is necessary to check gamma voltages.

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

hi Tom, couldn't find LVDS option anywhere on the service menu ?

[tom66]

Re: Inverted Colouras on Samsung LE37M87BD

What options do you have?

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

hope this helps Tom.

[tom66]

Re: Inverted Colouras on Samsung LE37M87BD

Ok, looks like no option for LVDS format, so time to focus on t-con.... good clear photo required.

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

Tom cant get a clear enough picture, broke my camera and my phone camera is a pile of sh*t... the T-Con board thats on it is T370HW02 V0. looked it up on ebay and they have a repair service for this specific board, costs £75 though and dont realy wanna spend that kinda cash when it might not even be the fault, the pins on the LVDS cable took fine and the board itself looks in excellent condition.

[budm]

Re: Inverted Colouras on Samsung LE37M87BD

Same board as this one:
https://www.badcaps.net/forum/showth...ng+LN37A550P3F

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

no Budm its exact same one attached (taken from Google images)

[budm]

Re: Inverted Colouras on Samsung LE37M87BD

I see, my version is 402, it does use the same AS15 Gamma Vref IC.

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

do you think that could be the problem ? how easy is it to fix, i have some soldering skills but dont think i could do something that complicated.....

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

I see, my version is 402, it does use the same AS15 Gamma Vref IC.

is that whats in place U603 ?

[budm]

Re: Inverted Colouras on Samsung LE37M87BD

U21 in your picture, and I believe the test points that Tom wants you to test is the row on the top right close to that IC. Tom can give you more details about testing those voltages.

[tom66]

Re: Inverted Colouras on Samsung LE37M87BD

You should test the points marked VGAMA1 thru VGAMA22. Meter on 20V DC, board installed in TV and showing pic, red pin on test point and black on chassis ground. Report your readings.

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

sorry for late reply guys, Tom did what you said got following readings..hope this helps..

VGAMA1 0.02
VGAMA2 0.18
VGAMA3 0.29
VGAMA4 1.84
VGAMA5 3.39
VGAMA6 4.92
VGAMA7 9.85
VGAMA8 12.35
VGAMA9 12.81-12.87 (was jumping up and down)
VGAMA10 12.92
VGAMA11 7.62
VGAMA12 15.02
VGAMA13 15.41
VGAMA14 15.38
VGAMA15 15.15
VGAMA16 14.84
VGAMA17 14.25
VGAMA18 14.14
VGAMA19 14.03
VGAMA20 14.01
VGAMA21 14.01
VGAMA22 14.00

[budm]

Re: Inverted Colouras on Samsung LE37M87BD

It is bad.

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

is it repairable Budm or will i just have to replace it ?

[Mikeyboy2007]

Re: Inverted Colouras on Samsung LE37M87BD

would this one do the same job, same number but from a different tv of a different size?

http://www.ebay.co.uk/itm/VIZIO-GV42...item27df6b3c9d