Hi, everyone--
I've got a Samsung UN55KU630DFXZA or UN55KU630DF, Version CA02, that does this:
1) Plug in power cord.
2) Backlight comes on and SMART TV logo is visible. This logo screen looks perfect. No sound (not sure if there is a startup sound or not).
3) Logo screen quickly turns off, backlight turns off.
4) After a few seconds, backlight comes on regardless of whether power button was pressed. Screen is black with backlight glow. No menu, no sound, none of the inputs work. I can press the joystick button in the back and the IR light flashes, but nothing happens (no sounds that would indicate moving around menus, etc.) TV will not turn off no matter what I do except pulling the AC cord out from the back.
A visual inspection of all the boards including the display drivers at the bottom edge of the screen didn't show any obvious burn or water damage marks.
Plugging a laptop in to the HDMI 1 input does nothing on the TV, but the laptop is aware that the TV is attached and is aware of the 4K resolution.
The power board is Samsung p/n BN94-10712A. A huge close-up photo is on ShopJimmy's site.
The mainboard is Samsung BN94-10838R. A huge close-up photo of that is also on ShopJimmy's site.
There does not appear to be a T-CON board.
I checked the voltages on the cable between the mainboard and the power board on the power board side while all boards were attached and the voltages all are within the spec silkscreened on the power board (They say 13V but another label clarifies that 13V is supposed to be 12.8V, which is exactly what I got).
EXCEPT: one test point J823 was a bit high. That pin's silkscreen said that while the TV is on, it should be 11.8V and while on standby, 7.5V. The actual measurement was 12.8V, which was the same as the output-to-mainboard pins, but I am not sure whether the TV is on or on standby while in this frozen state. Is 12.8V too high for 11.8V? Probably.
This feels like a mainboard issue and the power board is actually okay, but I don't want to buy a mainboard, drop it in, and have the power board kill it.
I found the EEPROM (label is IC1104) and tried shorting pins 5 and 6 on power on but nothing changed.
So, I'll go back and measure the power board and post up the values here, now that I have a better idea of how to measure the COLD and HOT sides.
Any tips or questions or a service manual/schematic are much appreciated.
I've got a Samsung UN55KU630DFXZA or UN55KU630DF, Version CA02, that does this:
1) Plug in power cord.
2) Backlight comes on and SMART TV logo is visible. This logo screen looks perfect. No sound (not sure if there is a startup sound or not).
3) Logo screen quickly turns off, backlight turns off.
4) After a few seconds, backlight comes on regardless of whether power button was pressed. Screen is black with backlight glow. No menu, no sound, none of the inputs work. I can press the joystick button in the back and the IR light flashes, but nothing happens (no sounds that would indicate moving around menus, etc.) TV will not turn off no matter what I do except pulling the AC cord out from the back.
A visual inspection of all the boards including the display drivers at the bottom edge of the screen didn't show any obvious burn or water damage marks.
Plugging a laptop in to the HDMI 1 input does nothing on the TV, but the laptop is aware that the TV is attached and is aware of the 4K resolution.
The power board is Samsung p/n BN94-10712A. A huge close-up photo is on ShopJimmy's site.
The mainboard is Samsung BN94-10838R. A huge close-up photo of that is also on ShopJimmy's site.
There does not appear to be a T-CON board.
I checked the voltages on the cable between the mainboard and the power board on the power board side while all boards were attached and the voltages all are within the spec silkscreened on the power board (They say 13V but another label clarifies that 13V is supposed to be 12.8V, which is exactly what I got).
EXCEPT: one test point J823 was a bit high. That pin's silkscreen said that while the TV is on, it should be 11.8V and while on standby, 7.5V. The actual measurement was 12.8V, which was the same as the output-to-mainboard pins, but I am not sure whether the TV is on or on standby while in this frozen state. Is 12.8V too high for 11.8V? Probably.
This feels like a mainboard issue and the power board is actually okay, but I don't want to buy a mainboard, drop it in, and have the power board kill it.
I found the EEPROM (label is IC1104) and tried shorting pins 5 and 6 on power on but nothing changed.
So, I'll go back and measure the power board and post up the values here, now that I have a better idea of how to measure the COLD and HOT sides.
Any tips or questions or a service manual/schematic are much appreciated.
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