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SiriusHardware · 11th Apr 2022, 4:39 pm

Can we have views of ALL of the terminals on that upper edge of the transformer and also a separate clear view of the label which is underneath the terminals? One possible pitfall here is that the transformer primary may have connections for both 110V in and 230V in.

That thin black wire dangling off the (mains?) switch is a death trap while it is like that so don't connect it to the mains again until you have made some sense of what goes where. With the half-view that we have of the terminals it seems like terminal 4 is a tap with (logically) terminal 2, out of sight in the photo, being the other end of the 230V winding. The tap could be a centre tap (ie, 110V) or it could be a tap for 220V with the whole winding being 240V.

I have to admit I'm worried - why has the mains side wiring been disturbed by the previous owner?

11th Apr 2022, 4:39 pm	#8
SiriusHardware Dekatron Join Date: Aug 2011 Location: Newcastle, Tyne and Wear, UK. Posts: 11,560	Re: Commodore CBM 4040. Can we have views of ALL of the terminals on that upper edge of the transformer and also a separate clear view of the label which is underneath the terminals? One possible pitfall here is that the transformer primary may have connections for both 110V in and 230V in. That thin black wire dangling off the (mains?) switch is a death trap while it is like that so don't connect it to the mains again until you have made some sense of what goes where. With the half-view that we have of the terminals it seems like terminal 4 is a tap with (logically) terminal 2, out of sight in the photo, being the other end of the 230V winding. The tap could be a centre tap (ie, 110V) or it could be a tap for 220V with the whole winding being 240V. I have to admit I'm worried - why has the mains side wiring been disturbed by the previous owner? Last edited by SiriusHardware; 11th Apr 2022 at 4:47 pm.