HDMI Inputs Have No Signal - Samsung UN65MU6290

[dumpstertv]

Hi all, I have a Samsung UN65MU6290 TV, and it works fine using its internal smart TV functions but I'm unable to get signal from any of the HDMI inputs. The optical audio out works, and there's one other component jack but I don't have the cables to test that. Checking the TV's diagnostics, the "HDMI SW IC" says "NG," so I assume the main board either needs to be repaired or replaced.

I saw some mail-in repair services, which I'm considering, but my main question is, if I choose to go the replacement route, do I need *exactly* the same board? There are a lot of seemingly identical variations of this board that are significantly cheaper on eBay and other sites, but the few exact model matches I've found are more expensive. (The board, or at least the main chip, model is BN94-12696B, made in October 2017.) If I got a replacement from a TV that's the same size, but slightly higher end, like a BN94-12696C or D, would the TV still function the same? Attached are photos of the TV self diagnostic and of the main board. Thank you!

[nomoresonys]

Might work, what I would do is tell the seller what you are trying to do and if you can send it back if it is incompatible, one thing you have to watch out for, will the board your getting connectors match up and will the back cover fit with the input output holes lining up. Had that issue on my own tv but just cut the back cover plastic out so the inputs were not covered, ugly but I don't look back there very often.

[neilc6]

Usually the last letter of a part number is the revision and a newer revision should be compatible for fit, form and function with older ones. That being said, I have seen a Samsung part with a different revision that was a completely different part so someone didn't follow the standard and it slipped through when it should have been a different part number.

[lotas]

If your native one is BN94-12696B, then you should replace it with BN94-12696B with the letter "B", with another letter "C" or "D" there may be incompatibility of the panel itself (matrix).

[CapLeaker]

For shits and giggles remove that metal shield. Follow the traces from the hdmi ports and they probably will go to the hdmi switch ic.

[dumpstertv]

Thank you all! I’m getting mixed advice but I guess the safest route is to either send in for repair or buy the exact same version of board. I will say that the C and D revisions of the board are visually pretty indistinguishable to me, I attached an image of a D board on eBay with mine on the left and the ports/components all appear to be in the same spots. I guess the issue lies in the compatibility with the specific panel. I also removed the shielding and found that the HDMI traces all lead back to the main CPU. Does this seem like an internal failure of the chip or something that heating the traces could solve?

[nomoresonys]

Try freezing up IC901 with some freezespray, get it good and cold, then try the hdmi, see if it works for a bit, could also try a factory reset if you didn't already and a firmware update, might not work but it's fixed things before.

[CapLeaker]

It’s not looking good…