On Thu, Mar 31, 2022 at 3:52 AM Noel Chiappa via cctalk <cctalk@classiccmp.org> wrote:
> If the machine then runs, it's up to you as to whether you get the P/S > repaired so that ACLO work properly - your call. (I wonder how the -15V got > to ACLO - I suspect a solder bridge from the prior repair - but knowing the > answer is not important to getting the machine running.) A short in FET Q15 on the bias/interface board in the PSU could do it. The gate of that FET is driven from an LM339 comparator the -ve supply of which is -15V. Of course _why_ Q15 failed, if it has, is another matter. -tony
