No picture.

[Steven.G]

The new cable was way too thick, so I rechecked and managed to get everything sorted, albeit temporarily as the cable is now only about 18" long.

But it now works as expected.

Steve..

[Steven.G]

Would this be a suitable replacement PSU cable,,
https://www.ebay.co.uk/itm/UL2464-26AWG ... SwNvBelS4c

[1024MAK]

Would this be a suitable replacement PSU cable,,
https://www.ebay.co.uk/itm/UL2464-26AWG ... SwNvBelS4c

26 AWG is the minimum conductor size that I would recommend. If this cable is really copper, then it should be okay.
However, the trouble is, this is coming from China via eBay. So I recommend you test it when it arrives to confirm it’s tinned copper cable as per the description and not anything else.

Get 6 core and double up the two wires going to the transformer centre tap / MTX 0V connections.

Mark