I haven't unsoldered anything to test yet, but who the hell is Samyoung and SamWha?! I've never even heard of these brands!
PS model number is BN44-00330A
better pictures will be forthcoming as soon as I find my scanner. There's no sign of heating damage anywhere. Symptom of set is that it completes POST with no problem. When turned on, all low voltage signals are operating normally, startup "chime" plays, then I hear two quick buzzes from the X/Y boards, both Vs and Va immediately start plunging and then the plasma goes out. This behavior is repeatable every startup. The jump start circuit and voltages seem to be fine at the instant the power on relays click over for the HV side. Just about dead on 205 Volts for Vs (calls for 205 Volt) and maybe 51 volts for Va (should be 55 Volts). The voltages drop to around 15 volts for Va and close to nil for Va.
This behavior also happens regardless of whether the X and/or Y boards are connected, just drops a lot slower without them connected. I'm fairly certain the rest of the set is still good and the problem is limited to the HV side of the power supply at the moment.
Does plunging / dropping Vs and Va sound like a cap problem ? I don't see anything vented but the set is just over 2 years old and has no fans in it, so I wouldn't be surprised if they were lackluster quality and just died.
I suppose it's also possible the secondary transformer has an arc or dies under load but that would seem unlikely that it would be ok at startup and then die every time even with no load. Also of note the center heat sink never gets warm to the touch even after quite a while of runtime.
Replacement power supplies seem to be plentiful on ebay and cheap but I suspect they all have the same problem.
PS model number is BN44-00330A
better pictures will be forthcoming as soon as I find my scanner. There's no sign of heating damage anywhere. Symptom of set is that it completes POST with no problem. When turned on, all low voltage signals are operating normally, startup "chime" plays, then I hear two quick buzzes from the X/Y boards, both Vs and Va immediately start plunging and then the plasma goes out. This behavior is repeatable every startup. The jump start circuit and voltages seem to be fine at the instant the power on relays click over for the HV side. Just about dead on 205 Volts for Vs (calls for 205 Volt) and maybe 51 volts for Va (should be 55 Volts). The voltages drop to around 15 volts for Va and close to nil for Va.
This behavior also happens regardless of whether the X and/or Y boards are connected, just drops a lot slower without them connected. I'm fairly certain the rest of the set is still good and the problem is limited to the HV side of the power supply at the moment.
Does plunging / dropping Vs and Va sound like a cap problem ? I don't see anything vented but the set is just over 2 years old and has no fans in it, so I wouldn't be surprised if they were lackluster quality and just died.
I suppose it's also possible the secondary transformer has an arc or dies under load but that would seem unlikely that it would be ok at startup and then die every time even with no load. Also of note the center heat sink never gets warm to the touch even after quite a while of runtime.
Replacement power supplies seem to be plentiful on ebay and cheap but I suspect they all have the same problem.
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