Samsung C27A550U LED -No Backlight- Need Doku

[Mr_K]

Here i habe a faulty C27A550U. The Unit has no backlight. Everything else is working fine.
The Main PCB is BN41-01652B with integrated LED driver. I can´t find any info or diagrams on the internet. Has anyone access to Samsung service files??? That would help a lot!!!

(The only thing i found is The "A" Revision on ebay)

Here is what i found so far:
The fuse for the LED Driver was blown. And blows again if replaced. (it´s located on the left in front of the big black coil)
When bridged, the display doesn´t start at all and the LED driver chip gets hot very quick.(located between the black coil and the flex connector) It is labled "bd9264efv" Can´t find any info on this one, too. Can you???

So, if anyone can help me with this one it would be great! Datasheets will help me a lot, too!!!!

[jetadm123]

Re: Samsung C27A550U LED -No Backlight- Need Doku

I don't see any photo. Try posting your photo using "manage attachments".

[Mr_K]

Re: Samsung C27A550U LED -No Backlight- Need Doku

*fixed* ....poor quality tough.....But thats the only one i found.

[Mr_K]

Re: Samsung C27A550U LED -No Backlight- Need Doku

I have finally fixed the backlight. OK: I almost did.....
There is a certain spot/area on the screen where is no backlight.


Is this an indication for a faulty panel???I hope it´s not!
I´m wondering if this might be caused by a bad flex cable from the main pcb to the panel. The contacts on one side are kind of "loose". They are "moving" on the foil.

I´d like to know your opinion on this one before i take any further steps. The cable is f**** expensive.....

[selldoor]

Re: Samsung C27A550U LED -No Backlight- Need Doku

Can you tell us how you fixed it - that would be a great help for the fuure and
maybe give us a clue as to why it is only partial?

Have you any pictures of your set - inside or just these "Library ones)

[Mr_K]

Re: Samsung C27A550U LED -No Backlight- Need Doku

Nothing special this time I just replaced the whole main board because there is absolutly no info about the LED driver chip nor was i able to get one for replacement.

I have no HQ picture of the inside....

Ok, could be a faulty replacement board but it was sold as tested and fully working. The question is: Is the backlight controlled "in one piece" (ON/OFF) or are there little segments with a seperate power supply and cable for each? It seems to me that these dark area is exactly one quarter of the screen. Maybe there are 4 seperate led segments and one has gone bad? Or the supply for one segment? Or just a bad cable so no power is coming through for one segment?

[selldoor]

Re: Samsung C27A550U LED -No Backlight- Need Doku

If you read this
http://reviews.cnet.com/2795-6482_7-399.html
It depends on what type of led tv it is. - Yours may be back lit with local dimming
so one section may be out. I did find a pic by googling (Led tv panel then images )
which shows the complex wiring arrangement.