> > One other thing… > With it powered on and measuring voltage at the outputs but not at the > plugs, wiggle the plugs a bit and see if there wierdness with them. > plugs and connectors go bad often and it doesn’t seem obvious that they do > but saves a lot of time just by checking them now. > > Sent from my iPhone > > > On Aug 31, 2025, at 13:34, Wayne S <[email protected]> wrote: > > > > Ps if you didn’t get continuity for a moment in one direction then the cap > > is > open. If you get continuity in both directions then it’s shorted. Hope this > helps. > > > > > > Sent from my iPhone > > > >> On Aug 31, 2025, at 13:28, Wayne S <[email protected]> wrote: > >> > >> Rob, replace c21 because of the bulge. If you want to check an > >> electrolytic > cap with a ohmmeter ,(kinda hard with a digital one), connect the meter > across the ends. You should get either infinite resistance or a momentary > reading of zero going back down to infinite resistance as the cap charges. > Then reverse the leads and it should be infinite from the start. > >> On an old analog meter with a dial, you can quickly tell by see the needle > deflect full scale in one direction then settle back down to infinite. I keep > an > old meter around just for this purpose. > >>
Replacing those caps seems to have fixed the issue, need to do a bit more testing. However I am unsure about some spikes on the +5V output when I try to check the ripple. This is the scope trace: https://rjarratt.wordpress.com/wp-content/uploads/2025/09/5v-output-ripple-after-replacing-caps.png Does that look reasonable or should I try to work out where these spikes are coming from? I replaced C21 and C35. Thanks Rob
