Chosen Solution
Hey All, Have been lurking this forum after a TV (listed in the title) came into my possession because the previous owner did not want to deal with it. I was originally going to buy if off of them. During the testing ( I wanted him to verify it was working before purchase), everything was going good, until he decided to plug it into a very old and not likely protected power strip. The screen went blank when he did this, it had the constant relay clicking, with the red standby light flashing 8x during the cycle. It just repeated and sounded like a power cycle. He offered to give me the TV for free because he didn’t want to deal with it. After reading a bunch of threads on here and performing test, I bought a new power supply and installed it. The problem persisted. I took some voltage readings at the power supply and all were normal. Here is a breakdown of what’s happening now: The TV is not powering on, as I mentioned it’s power “cycling”. Ie relay clicking but no image. Backlights work when connected directly to power so the LED’s are functioning.With the TCON and Main Board disconnected from power supply, no power supply relay clicking and LED Backlights come on no issue when the TV is plugged in. No red standby LED because main board is not connectedWith the TCON connected to the power supply and the Main Board disconnected from power supply (but connected to the TCON), no power supply relay clicking, but I get no backlights or screen image. No red LED standby light flashing either (bottom right of the TV frame)With TCON and Main Board connected to power supply, power supply relay clicks in a repeatable cycle like it’s trying to power on and off, but there is no backlights or no screen image. Red standby LED flashes 8x in a cycle with the relay on/off clicking.I have the old and a new power supply, both are good as they power on the backlight LED’s when the TCON and main boards are disconnected. I lose backlight LED’s when either the TCON or Mainboard are plugged into the power supply. I know the main test is to disconnect just the main board from the power supply and if the backlights come on, then it’s the main board usually. But when I disconnect the main board (but leave it connected to the TCON), I don’t get backlight display and the clicking/power cycle stops. I have a TCON board coming (new) because it’s a $10 board vs $100 for the main board, but I’m wondering everyone’s thoughts on what it could be? My issue differs from most because it takes me disconnecting the TCON AND main board to get LED backlights. FWIW, all the LED backlights work. I can see them through the back screw holes and I can see on the screen as well. Thanks in advance!
For anyone that comes back and reads this thread, it ended up being a bad main board. Once the main board was swapped out, all was good again. It seems that there are many different combinations of symptoms so this one happened to be the main board that solved it for this model. Appreciate all of @oldturkey03 ’s help with this
@krashdh your T-con board and your main board sort of need each other. This does sound more like a main board issue. You should actually go ahead and measure the voltages on the connector between the power board and the main board and let us know what you get. Also, on the T-con board, usually where the ribbon cable from the main board connects to, should be a fuse. Labelled as F1 or close to the like F1000 etc. Measure the voltage on that. You can also post some good pictures of your boards with your question. That way we can see what you see Edit your QUESTION and use Adding images to an existing question this guide Oh and just to clarify, disconnecting the main board from the power board and the backlight turning on, is only a test for the power board. If they do come on, it’s a good power board bad main board :-)
I am a Samsung Authorized Service Center. In this case you either have a bad main board or the the cables are bad. Need to replace cables along with the boards. Sometimes the cables can go bad also. With the back lights coming on when the main board is disconnected I would lean towards the cables since you have already replaced the main board. However you may gotten a bad main board.
