samsung un65nu6900f common problem, digging deeper

[petersor]

Some more data points as I'm working on one of these right now. I've tried 15k & 22k resistors for R13246 so far. The TV starts fine with either, but as soon as I add an HDMI Signal to either input, it stops booting. If I plug the HDMI in after it boots, the picture goes dark but the sound remains . . . I'm going to play with a few other resistor values, starting with 10k and then 4.7k to see if it will boot with HDMI connected. I'm wondering now if this is possibly and HDMI issue . . .

Rich

[petersor]

Follow-up to my previous post. 10k resistor in R13246 caused a boot loop so I tried a few higher values - 27k, 33k & 47k. All allowed the TV to function properly with great picture so I left the 47k resistor installed and put it all back together. Everything works fine using the built-in streaming services, but my Amazon FireTV produces sound but no picture through either HDMI port. I'm thinking it's probably due to a setup issue that I'll investigate, although I would think it should be plug and play. I can live with onboard streaming for now.

I took a few voltage measurements on R13246 about halfway through the resistor swaps so I'll share those. Voltage at the 'top' of the resistor was consistently around 25.x V:

27k - 19.6V
33k - 18.7V
47k - 16.6V

Rich

[nomoresonys]

Follow-up to my previous post. 10k resistor in R13246 caused a boot loop so I tried a few higher values - 27k, 33k & 47k. All allowed the TV to function properly with great picture so I left the 47k resistor installed and put it all back together. Everything works fine using the built-in streaming services, but my Amazon FireTV produces sound but no picture through either HDMI port. I'm thinking it's probably due to a setup issue that I'll investigate, although I would think it should be plug and play. I can live with onboard streaming for now.

I took a few voltage measurements on R13246 about halfway through the resistor swaps so I'll share those. Voltage at the 'top' of the resistor was consistently around 25.x V:

27k - 19.6V
33k - 18.7V
47k - 16.6V

Rich

That is curious, did you try another hdmi device or another hdmi cable?

[Diah]

satsified

Follow-up to my previous post. 10k resistor in R13246 caused a boot loop so I tried a few higher values - 27k, 33k & 47k. All allowed the TV to function properly with great picture so I left the 47k resistor installed and put it all back together. Everything works fine using the built-in streaming services, but my Amazon FireTV produces sound but no picture through either HDMI port. I'm thinking it's probably due to a setup issue that I'll investigate, although I would think it should be plug and play. I can live with onboard streaming for now.

I took a few voltage measurements on R13246 about halfway through the resistor swaps so I'll share those. Voltage at the 'top' of the resistor was consistently around 25.x V:

27k - 19.6V
33k - 18.7V
47k - 16.6V

Rich

however you are satisfied but this is not enough.. as you dismissed the frame rate Freq & resolution...

That is curious, did you try another hdmi device or another hdmi cable?

no way even if cable in high resolution.

[petersor]

I played with the setting on the FireTV and the TV a bit and it's now working perfectly. I think the TV is supposed to auto-detect the resolution, F/R etc. so maybe it was something on the FireTV side. Either way, problem solved.

Rich

[nomoresonys]

Ok, you were right about it just being a settings tweak, was my first thought as well.

[petersor]

Quick update - still working well after 5 months . . .

[nomoresonys]

This is a very informative thread and can potentially save a lot of these tvs, I think it should be a sticky so it is easy to find. Owner would probably have to do it, I don't think the mods have the mentality.

[nomoresonys]

Since it's not likely to be stuck, you can bookmark or save, maybe subscribe for future access but my subscribes vanished.

[itelite]

Ive done a few more of these over the years. When the problem matches that as originally posted, the resistor swap seems to work. The suitable resistor value does seem to vary though. Ive found putting a small potentiometer in the place of the resistor is great to make the fine adjustments to resistance required to get the best picture. You can turn the pot and watch the color saturation change until you get too high or too low of a resistance (causing a reboot). You can then either leave it, or measure the resistance and replace it with a SMD resistor of the same or very close value.