Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

[What?]

A friend brought this TV to me 'cause he knows I like to tinker. No stand and no remote control. I have taken some measurements so what would you like to see first.
I plug the TV in, no apparent activity. Push the on/off button nothing happens.
Took the back cover off, plugged in the TV and it looks like the PSU is working because there are voltages at the connector going to the Main board. When I unplug the Main board from the PSU the backlights come on but nothing else happens. Still no sound no standby light, no image.
I have already replaced the eeprom chip with the ShopJimmy repair kit for this board. Made no difference.

[budm]

Re: Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

"When I unplug the Main board from the PSU the backlights come on but nothing else happens. Still no sound no standby light, no image."
So the power supply board self test shows that it is working, and of course the main will do nothing since there is no power to the main board when it is not connected to the power supply.
The connector of the power supply board that goes to the main board has pin names to tell us what each pin is for, so put all the connector in place then report the Voltage reading of each pin when TV is plugged in and when the power switch is activated, you MUST PUT DOWN THE PIN NAME AND FOLLOW BY THE READING FOR EACH PIN so we can easily what it has or does not have.
BN44-00499A PS board.

[CapLeaker]

Re: Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

sounds like a bad main board to me. No stby light isn't a good sign. There are 2 possibilities. Either there is no STBY voltage going to the main IC on the main board, or that main IC is bad and you need a replacement main board.

[What?]

Re: Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

Thanks for your reply, the following is voltage readings on connector CN803 which is the connector on the BN44-00499A PS that connects to the Main board.

PIN # ID voltage
1 B13V 13.06
2 PWM_DIMM 0.084
3 B13V 13.06
4 B13V 13.06
5 Vamp 13V 13.06
6 BLU On/Off 4.96
7 Vamp 13V 13.06
8 GND 0
9 GND 0
10 GND 0
11 B5V 5.355
12 A5V 5.355
13 B5V 5.355
14 Power On/Off 3.58

Pushing the power button makes no difference. I checked the connector pins for the power button, there is 3.3v on 2 pins all the other pins are 0v

[budm]

Re: Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

AT least pin 14 (PS-ON control signal for turning the rest of the power supplies on and off) should toggle between <1V and > 2V when toggling the power switch.
The 2 PWM_DIMM 0.084 is also bad so there will be no backlights.
At this point there is something bad going on with the main board.

[What?]

Re: Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

Thanks budm and CapLeaker for responding.
Something bad meaning proprietary chips? Can it be fixed or should I just toss it and look for another Main Board?

[What?]

Re: Samsung UN50EH5000F No Image, No Backlight, No Sound, No Standby Light

Thanks to Dick Barton for posting the troubleshooting guide for Samsung!