Samsung UE40MU61 no red led but backlight

[kevvort]

Hi all!
I've a Samsung UE40MU61 that's not showing the red led when it's in stand-by nor turns on.
I diagnosed the power board and looks like it's fine + if I disconnect the main board all the panel backlights turn on so I suppose, based on what I've found, that the power board should be ok.
Then I moved to the main board BN41-02568B and after some googling I've found this forum where a lot of people reported that the issue could be in the FW contained in the W25Q40CL chip.
I got my reader and dumped it but it doesn't look like it's corrupted because there's data in the first 0x1000 addresses.

I also checked the joystick and voltages are ok but the red led voltage is totally missing.

Do you have any tip for me? For being sure I'll attach my dumped firmware.

Thanks a lot

[lotas]

Re: Samsung UE40MU61 no red led but backlight

What a strange Dump you have, it looks like a Dump from T-con (25Q80), you didn’t accidentally mix up the chips.

[kevvort]

Re: Samsung UE40MU61 no red led but backlight

You were absolutely right, my bad... here as attachment my 1604 dump with a lot of FF in the first areas

Just for curiosity: do you just restore the first 0x1000 addresses or do you do something else?

[lotas]

Re: Samsung UE40MU61 no red led but backlight

Try it, do not forget about the Status Register, but I restore the "header" with the correct version of the software.

[kevvort]

Re: Samsung UE40MU61 no red led but backlight

Try it, do not forget about the Status Register, but I restore the "header" with the correct version of the software.

Got it and ok about the status register, I did it.
Now the red led is on, I can turn on the TV but I've a black screen with backlight, then looks like it bootloops.

Any tips?

[lotas]

Re: Samsung UE40MU61 no red led but backlight

Well, maybe they damaged or incorrectly, somehow they recorded a dump in 25Q80 (you didn’t do anything with it?).

[kevvort]

Re: Samsung UE40MU61 no red led but backlight

Well, maybe they damaged or incorrectly, somehow they recorded a dump in 25Q80 (you didn't do anything with it?).

Unfortunately yes, I tried to restore the content but it's a 25Q80 and I dumped it as a 25Q40 so I miss half the data

Are IC1604 and 1603 coupled? I think I can at least try to find a IC1603 dump and merge the first half with mine but I need to be very lucky...

Do you think it's the best thing I can do other than beating my head?

[lotas]

Re: Samsung UE40MU61 no red led but backlight

Now you need to look for exactly the same dump 25q80 that was originally, it contains all the settings and data of your panel, what is the number of your panel?
And the full model of the TV itself and the motherboard number BN94-xxxxx?

[lotas]

Re: Samsung UE40MU61 no red led but backlight

Are IC1604 and 1603 coupled? I think I can at least try to find a IC1603 dump and merge the first half with mine but I need to be very lucky...

These are completely different dumps, and each is responsible for his own, and there is nothing to combine in them, there is no need to cross.

[Diah]

Re: Samsung UE40MU61 no red led but backlight

since TV go to STB and turn on... all other issue can be solved by service menu call from STB

[kevvort]

Re: Samsung UE40MU61 no red led but backlight

TV full model: UE40MU6120KXZT
Board: Code: BN41-02568B
MODEL: BN41-02568B
MOEDL: KANT_M_BUILT_IN

So every dump should work or are there any keys that should match with other components?

[lotas]

Re: Samsung UE40MU61 no red led but backlight

since TV go to STB and turn on... all other issue can be solved by service menu call from STB

What is the service menu if it completely killed the dump T-CON.

[lotas]

Re: Samsung UE40MU61 no red led but backlight

TV full model: UE40MU6120KXZT
Board: Code: BN41-02568B
MODEL: BN41-02568B
MOEDL: KANT_M_BUILT_IN

So every dump should work or are there any keys that should match with other components?

I need the number not BN41-xxxx, but the number BN94-xxxxx (it is on a white tag pasted on the motherboard), and I asked for the number, panel (matrix) model.

[Diah]

Re: Samsung UE40MU61 no red led but backlight

What is the service menu if it completely killed the dump T-CON.

T-CON are for freq rate displaying.. S;M are simple rate don't depend on any high resolution T-CON support

[lotas]

Re: Samsung UE40MU61 no red led but backlight

T-CON are for freq rate displaying.. S;M are simple rate don't depend on any high resolution T-CON support

In these models, if the dump T-CON (25Q80) is damaged, then there will be no image, only the backlight!

[lotas]

Re: Samsung UE40MU61 no red led but backlight

kevvort try dump 25Q80

[Davi.p]

Re: Samsung UE40MU61 no red led but backlight

Hi, can you explain to me better? You have read the tcon memory as a 25Q40, after this you noticed was the wrong memory, so you haven't write any thing on that right? If this is the case you probably has a fault in the panel..

[kevvort]

Re: Samsung UE40MU61 no red led but backlight

kevvort try dump 25Q80

Thank you Lotas, it worked!
Now I'll test deeper if everything is fine but I think I'm ok.