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I have a un60h6203af there was no power so I replaced both main board and power supply they were cheap enough. When I put it back together I plugged it in and standby light was on but noticed didn’t plug in backlights when I did plug in back light cable the standby light went off and no power again so I’m not sure why the backlights would be making the tv get no power? So it still will not turn on to even see a menu screen dim or to hear if there’s sound so I can’t tell if it’s a t con or backlights never had this problem before need some help please
Hi @jdegregz , Start back at the beginning. All boards and cables in and connected correctly. Connect power to the TV Standby light not on - check voltage on power board standby power test point as marked on the power board. Think it is ~7.5V but not sure. If no voltage check fuse on power board Standby light on - disconnect power from the TV and then disconnect the cable between the power board and the mainboard. Reconnect the power to the TV and turn on the TV. The TV LED backlights should turn on full and stay on. There will be no picture because the mainboard is disconnected. Backlights not on - check voltage at LED connector on power board. >220V DC problem with LED array. <50V DC problem with power board Backlights on - turn off TV and disconnect the power. Reconnect cable between the mainboard and the power board. Reconnect power to the TV, standby light on then turn on the TV. If TV turns on but no audio or display check the voltages as marked on the power board near the cable going to the mainboard. Also using a torch shine at an angle close to the screen to check for images. They will be very faint so if possible try in a darkened room to help see them if they are there or not. If still no display or audio and power board voltages are OK then probably a mainboard problem. Hopefully a start.
@jdegregz disconnect the main board from the power board. That should turn your back lights on. If your back lights do not come on then the issue is most likely a bad backlight array. This TV set is very known to have bad LED’s. Turn the TV on and measure the VDC of the BLon pin on the PSU, in order to make sure the main board is actually turning on the back lights. Should be pin 5 on CNM803 (somewhere in the 4V range to turn BL on) Measure the voltages on your power supply leading to the backlight LED’s and let us know what you get. DC voltages can be high, so set your meter to around 5-600 V scale and black probe to ground.
Back light. Once one LED dies the entire strip dies.
