Samsung LE37R87BD - Sound but no picture.

[donst]

Hi all, looking for some help with a Samsung LE37R87BD.

The TV set has no picture but does have sound. At first i thought the issue may be with the AV panel, but i've since replaced the supposed bad AV panel with one that i know is in full working order, and the problem persists.

When the TV set is first turned on the backlight turns on for a split second and also displays the extension, but no picture. When removing the cable and plugging it back in again on the inverter board the picture displays for about a second. The same occurs when you wiggle it about. The same also happens with a cable on the AV board. I have highlighted both cables that i am referring to in the first image that i have attached. I have also added other images that may be of use.

Anyone with any ideas?

All help much appreciated.
Thanks,
Don.

[donst]

Re: Samsung LE37R87BD - Sound but no picture.

Anyone?

[mattstolte]

Re: Samsung LE37R87BD - Sound but no picture.

Main board

[donst]

Re: Samsung LE37R87BD - Sound but no picture.

Main board

That's what i thought, but i replaced the main board with one that i know is working and still the issue persists.

[selldoor]

Re: Samsung LE37R87BD - Sound but no picture.

You should not be plugging/unplugging cables with it powered on.
Try unplugging the many stranded blue and white cable from the main board
( lvds that goes to the Tcon) To see if the panel lights up - it wont have a picture

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

So you have 2-second to black problem. Did you verify that the 24VDC and the BL_ON are present at the inverter board?
That inverter board uses DARFON inverter transformers which is known for going bad alot, If you do have 24VDC and bl_on, fuses, then you need to check the HV windings of the inverter transformer next.

[donst]

Re: Samsung LE37R87BD - Sound but no picture.

Thanks for the reply

Ok, just tried unplugging the lvds cable from the main board and nope the panel does not light up. Everything remains the same.

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

You did check all the fuses on the inverter board, right?

[donst]

Re: Samsung LE37R87BD - Sound but no picture.

Hi budm, thanks for the replies.

Yes, sorry i should have mentioned in my OP that i measured all fuses on inverter. All fuses (f2-f5) measure at 24v.

Regarding your previous post, sorry i'm not entirely sure what either the 24vdc or the BL_ON fuses exactly are or where they are to be located?

Thanks again.

Edit: Also worth mentioning that two blown caps (cm860 and cm870) were found on power board that i subsequently replaced.

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

OK, so the 24V is OK then since it shows up on the fuse,
The B;_ON will be on the white connector on the inverter board, I will need good clear pictures of around that connector, also give me the P.N as printed on the inverter board so I can see if shopjimmy will have the pictures of your board.
We also need the numbers as printed on the top of the inverter transformers so we can look up the pin out of the transformers for checking the resistance of the high voltage windings of the transformer.

[nomoresonys]

Re: Samsung LE37R87BD - Sound but no picture.

probably is bad inverter, didnt even see one on sj or ebay.

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

It looks like this one but not 100% sure since the pictures are not in focus.
http://www.shopjimmy.com/auo-19-2600...t-inverter.htm
There is no label for the pins either.
Strange thing is that there are two P/N for the transformers, it uses 6009b and 6010b.
Check the resistance of each winding of the transformer using 2K Ohm scale, they should be within 3% from each other.

[nomoresonys]

Re: Samsung LE37R87BD - Sound but no picture.

It looks like this one but not 100% sure since the pictures are not in focus.
http://www.shopjimmy.com/auo-19-2600...t-inverter.htm
There is no label for the pins either.
Strange thing is that there are two P/N for the transformers, it uses 6009b and 6010b.
Check the resistance of each winding of the transformer using 2K Ohm scale, they should be within 3% from each other.

24 bucks, seems like a good deal.

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

Yep, it is very reasonable price.

[selldoor]

Re: Samsung LE37R87BD - Sound but no picture.

His 6026B
http://www.amazon.co.uk/Inverter-Tra.../dp/B00MWRJDW0

[nomoresonys]

Re: Samsung LE37R87BD - Sound but no picture.

His 6026B
http://www.amazon.co.uk/Inverter-Tra.../dp/B00MWRJDW0

about 18 bucks vs whole board for 24.

[selldoor]

Re: Samsung LE37R87BD - Sound but no picture.

about 18 bucks vs whole board for 24.

Yes one transformer is rarely a good buy and if one has gone chances are others will follow. Parts in the uk are generally dearer than in the US-
I was just saying that the Transformers on his board have a different number to the two that budm suggested and the amazon ad was to show the 6026B and the pinout.

If it is determined that there is a faulty transformer a board can be obtained here https://flattvparts.co.uk/samsung-le...1-19.26006.342 for GBP 24 +GBP5.50 post which overall I guess will work out cheaper than from the US.

@budm Interestingly this board also has a mixture of transformers they are 6026B apart from 2 x 6025B on the left side. ( I cant read the end ones on his original board)

[donst]

Re: Samsung LE37R87BD - Sound but no picture.

OK, so the 24V is OK then since it shows up on the fuse,
The B;_ON will be on the white connector on the inverter board, I will need good clear pictures of around that connector, also give me the P.N as printed on the inverter board so I can see if shopjimmy will have the pictures of your board.
We also need the numbers as printed on the top of the inverter transformers so we can look up the pin out of the transformers for checking the resistance of the high voltage windings of the transformer.

Ok, i've taken a picture around the connector, it's not the sharpest but i can't get it any sharper. See attached photo.

Transformers 1-6 : 6026876NB16 (GP) -04
Transformers 7-8 : 625B76TF04 (GP) -04

Inverter P.N : E206453 V144

I've also measured all windings of transformers and 1-8 (1 being top) and they all measure around 1.4k to 1.7k except for the second one. The second transformer, the top winding measures absolutely nothing whilst the bottom winding does. The problem?

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

I am not sure yet as tho why it uses kinds of transformers (as shown 2SJ, 6009B, 6010B), They look to have the same spec.
6009B: http://lcdparts.net/TransformerDetai...ProductID=2794

6010B:http://lcdparts.net/TransformerDetai...ProductID=2795

He should at least test the resistance readings first.

[budm]

Re: Samsung LE37R87BD - Sound but no picture.

Ok, i've taken a picture around the connector, it's not the sharpest but i can't get it any sharper. See attached photo.

Transformers 1-6 : 6026876NB16 (GP) -04
Transformers 7-8 : 625B76TF04 (GP) -04

Inverter P.N : E206453 V144

I've also measured all windings of transformers and 1-8 (1 being top) and they all measure around 1.4k to 1.7k except for the second one. The second transformer, the top winding measures absolutely nothing whilst the bottom winding does. The problem?

May be the flux is covering up the pins, try applying the solder to the legs and check again, but it sounds like you have found the problem.
You can remove that suspect transformer and test it again.