> -----Original Message----- > From: Christian Corti via cctalk <[email protected]> > Sent: 11 September 2025 08:31 > To: Rob Jarratt via cctalk <[email protected]> > Cc: Christian Corti <[email protected]> > Subject: [cctalk] Re: Repairing an Olivetti M24 PSU > > On Sat, 6 Sep 2025, Rob Jarratt wrote: > > I thought that replacing two big output capacitors on the +5V output > > had fixed the issue but it hasn't. The problem seems to be > > intermittent. I tested it a couple of days ago with a simple resistive > > load on the +5V and +12V outputs. The first two times I switched it on > > it operated normally. The third time I got no output at all. It seems > > to start working again after I leave it switched off for a few > > minutes. Over the last couple of days I have tested it multiple times > > very briefly with the resistive load and it has worked every time. > > Did you test/replace the startup voltage capacitor on the primary side? It is > usually a small one (e.g. 10µF/50V) around the switching controller, and often > located near a heat sink and thus prone to fail. > BTW check all capacitors near heat sinks or power components. > > Christian
I tested most electrolytics for ESR in-circuit. When I am back home I will see about opening up the PSU again and checking this and all the other things that I have had suggested. Thanks Rob
