Swapping 33nF caps C29,31,38,50,103 for fresh parts dropped the current down to a much more sane sub-800mA. Ooof.Pulled out the thermal camera for some clues - oof there's some decoupling caps up at 80C, that's not good - I did think the board was drawing more than it should (1.3A). I guess I'll swap those caps.
And the machine booted on the 2nd (?) try after doing that and has been ok since.
EDIT: Further thermal camera sleuthing shows up another 6 caps that are farrr too hot. More to do. And three of those aren't really anywhere near the battery. Rather interestingly though, all 11 of these caps are the same 33nF value -- bad batch? I don't believe that can be coincidence.
EDIT2: With those extra 6 caps replaced, we're down to just under 600mA in desktop. Lovely. That's less than half what the board was originally drawing, just by changing 11 capacitors.
Statistics: Posted by IanJeffray — Mon Dec 30, 2024 12:57 pm