Hi guys, I've got in a Proel stage 4 class D amplifier in for repair. The fuse blown and I measured a short upstream from the bridge rectifier +Ve and -Ve. The two shorted components were the High and Low Mosfets. Gate-drain-source shorted on both. After removing the two mosfets the short has cleared when measured from the rectifier.
I haven't figured out the root cause for the failure but I have measured one dual diode on the secondary side (channel 1) which is shorted. I would need to further investigate.
My question is what other things I should look for while trying to fix this? I don't want to be just replacing MOSFETs just for them to blow up. What would be the best strategy?Could this short on the secondary side cause this kind of failure of the transistors?
I tried to look for schematic for the model but couldn't find one, by the looks of it it looks like a standard IR2153 circuit with feedback.
Thanks for the help.
P.s: there is some kind of 'oilish' substance on the dual diodes on both the channels.
I haven't figured out the root cause for the failure but I have measured one dual diode on the secondary side (channel 1) which is shorted. I would need to further investigate.
My question is what other things I should look for while trying to fix this? I don't want to be just replacing MOSFETs just for them to blow up. What would be the best strategy?Could this short on the secondary side cause this kind of failure of the transistors?
I tried to look for schematic for the model but couldn't find one, by the looks of it it looks like a standard IR2153 circuit with feedback.
Thanks for the help.
P.s: there is some kind of 'oilish' substance on the dual diodes on both the channels.
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