So, got my aleph5 constructed. After testing power supply, hooked up both channels as had made these boards before to test them out and usually meticulous on stuffing.
killed my fuse after starting up, about 1minute after start up. how long does it take for cl40 thermisistor to open up fully?
so, trimmed down to just one channel works fine, minimal to no significant offset. let that run about 45 minutes, heat sinks holding up well.
went back disconnected working channel, connected untested channel.
had tiny tiny puff of smoke, fuse blew about 10 seconds. near the + side first output fet.
they are to3p devices and use alum oxide pads so not suspecting broken insulation like when using silpad etc.
Is it likely to be a damaged output fet? Wondering if damaged it overheading the drain during soldering - seems to soak up more heat than gate or source.
I suppose could replace the mpsa18's while in there to be safe... Can it be powered up with out the irfp240's to test?
killed my fuse after starting up, about 1minute after start up. how long does it take for cl40 thermisistor to open up fully?
so, trimmed down to just one channel works fine, minimal to no significant offset. let that run about 45 minutes, heat sinks holding up well.
went back disconnected working channel, connected untested channel.
had tiny tiny puff of smoke, fuse blew about 10 seconds. near the + side first output fet.
they are to3p devices and use alum oxide pads so not suspecting broken insulation like when using silpad etc.
Is it likely to be a damaged output fet? Wondering if damaged it overheading the drain during soldering - seems to soak up more heat than gate or source.
I suppose could replace the mpsa18's while in there to be safe... Can it be powered up with out the irfp240's to test?
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.