Re: Panasonic TH-42PX70B Blowing mains fuse.
Nice , So all those were bad or were the driver and smd FETs just precautionary?
Both of the smd fets were bad, one was o/c, the other had a constant resistance of 57ohm between gate and source.
Not sure about that driver chip, did not know how to test it, and did not want to start probing the new one i bought for comparison to the old one in case i damaged it. The new driver chip only cost a couple of quid, so i decided to swap it, just in case it was bad. And seeing that there were so many components in that circuit that had failed, i think it was likely the chip also had a fault.
I will say one thing, i am glad i had a small tip for my iron, those fets were tiny. I had some flux paste, so i used that to stick them down in the right place before i soldered them.
Tv seems to be happy running with the 0.22ohm ceramic resistors in place of the 0.12ohm it should have. I have now found a source for the correct value ones in Germany, so have ordered a couple. http://www.ebay.co.uk/itm/3605151691...84.m1439.l2649 Had to settle for axial in the end, but they should fit ok.
Originally posted by tw2005
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Nice , So all those were bad or were the driver and smd FETs just precautionary?Not sure about that driver chip, did not know how to test it, and did not want to start probing the new one i bought for comparison to the old one in case i damaged it. The new driver chip only cost a couple of quid, so i decided to swap it, just in case it was bad. And seeing that there were so many components in that circuit that had failed, i think it was likely the chip also had a fault.
I will say one thing, i am glad i had a small tip for my iron, those fets were tiny. I had some flux paste, so i used that to stick them down in the right place before i soldered them.
Tv seems to be happy running with the 0.22ohm ceramic resistors in place of the 0.12ohm it should have. I have now found a source for the correct value ones in Germany, so have ordered a couple. http://www.ebay.co.uk/itm/3605151691...84.m1439.l2649 Had to settle for axial in the end, but they should fit ok.
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