Chosen Solution
My Samsung 60” UN60H6350AF suddenly failed - no picture, no sound and no standby. I checked the PS board BN44-00705A and found if I disconnect the cable to the main board (CNM803), the backlights go on. With main cable disconnected voltage on CNM803 Pin4 (BLU_ON) is 3.2V and Pin 6 (PS_ON) is 4.4V - both seem low. I replaced the main board and tcon boards but same issue remains. I am not 100% sure the replacement main board and tcon boards are good however (bought used/seller indicated they are 100% operational). Could the PS board be bad? What else should I check? Thanks much!
Hi - I resolved the issue. Unfortunately, I was sold a defective replacement mainboard! I obtained a repair of my original mainboard and the TV is working perfectly now. Thanks for all your support and guidance - most appreciated!
Hi @mgoodmaster With all cables connected and power connected to the TV etc, check the standby voltage as indicated on the power board is OK. Can’t read it too well when zoomed in, in this image but the ref. point is marked in the Cold section of the board, top right corner of the image. If the voltage is not OK then the problem is the power board. If the voltage is OK then disconnect the power to the TV and disconnect the mainboard - power board cable (both ends) and check the cable wires for continuity - end to end, just to eliminate it as the problem. It is the mainboard that turns on the Standby power LED if the standby voltage is OK coming from the power board.
