Hi folks,
I have a Samsung plasma tv PL51F4500. It works fine, image is good, but it shocks me a little when i touch it or touch a connect hdmi cable. So my concern is mostly for anything i connect to it, my notebook etc. Interestingly, i had stopped using it and went to turn it on yesterday and it basically doesn't 'shock' me anymore. The observation here is that its a lot better than when it was in regular use. It was pretty salty!
This model has an integrated sustain board with the main power supply. I repaired it about 2 years ago (mosfets) but i may have missed a further issue since the tv worked fine.
I have no doubt the problem is isolated to the main power/sustain board. I isolated it and the problem persisted. I can measure a voltage between my hand and tv gnd to observe this, and the tv will 'shock' even in standby, but it will stop the moment i unplug the lead. So surely this means the problem lies in the line filter? and since the problem has improved after the tv was left off for a month indicates a bad cap right? But i haven't found anything yet.
Va and Vs are both within 2 volts of specified 58v and 205v.
All the various outputs to the main board are all spot on, 5.3v, 15v and so on.
But the SVT_VS is 550volts! and the SVT_XOUT is 'out of range'!?! With the scale of 1000v DC selected, the multimeter goes to 1. I'm assuming that this isn't right. Searching around i found that a similar model had a XOUT of 71 volts. So this would indicate a problem with rectification right?
Nothing on the board is visually damaged. I even scanned the board with my laser temp gun, there was one mosfet hotter than the others which i removed and tested fine. I've gone over all the mosfets on the sustain side of the board, no issues. I removed a couple caps for testing.
I was lacking direction but just writing this question has help. I guess i'll go back to the start.
Any got any ideas?!
Cheers,
Mike
I have a Samsung plasma tv PL51F4500. It works fine, image is good, but it shocks me a little when i touch it or touch a connect hdmi cable. So my concern is mostly for anything i connect to it, my notebook etc. Interestingly, i had stopped using it and went to turn it on yesterday and it basically doesn't 'shock' me anymore. The observation here is that its a lot better than when it was in regular use. It was pretty salty!
This model has an integrated sustain board with the main power supply. I repaired it about 2 years ago (mosfets) but i may have missed a further issue since the tv worked fine.
I have no doubt the problem is isolated to the main power/sustain board. I isolated it and the problem persisted. I can measure a voltage between my hand and tv gnd to observe this, and the tv will 'shock' even in standby, but it will stop the moment i unplug the lead. So surely this means the problem lies in the line filter? and since the problem has improved after the tv was left off for a month indicates a bad cap right? But i haven't found anything yet.
Va and Vs are both within 2 volts of specified 58v and 205v.
All the various outputs to the main board are all spot on, 5.3v, 15v and so on.
But the SVT_VS is 550volts! and the SVT_XOUT is 'out of range'!?! With the scale of 1000v DC selected, the multimeter goes to 1. I'm assuming that this isn't right. Searching around i found that a similar model had a XOUT of 71 volts. So this would indicate a problem with rectification right?
Nothing on the board is visually damaged. I even scanned the board with my laser temp gun, there was one mosfet hotter than the others which i removed and tested fine. I've gone over all the mosfets on the sustain side of the board, no issues. I removed a couple caps for testing.
I was lacking direction but just writing this question has help. I guess i'll go back to the start.
Any got any ideas?!
Cheers,
Mike
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