Sir BrianBro . . . . . . .
Since that power supply is probably only going to handle a 20 amp output . . .reliably . . . first question will be how much is your test load with that mere 5VDC output ?
Then, we need to analyze to see if the fault is being with the initial raw DC supply or with the regulator circuitry on the side board.
The Raw dc supply is at the somewhat smaller
RED wire, which I have marked with the
YELLOW arrow.
The
BLACK arrow is the regulator board
The PINK arrow denotes the cluster of 6 electrolytics . . .4700 motherly-farads each. . . .I believe .
. . . which are being the storage bank for the raw DC supply.
You need to meter the DC voltage being between negative terminal on the FRONT panel, as ground referencing, and the
RED wire, I earlier pointed out, with the unit initially unloaded, and then confirm, what the unloaded supply initially has for being its total supply capability.
Also measure it in AC mode and record.
Then load down the supply and confirm what the raw DC voltage is then changing to, as well as what the AC voltage content, then changes into.
Come back to me with those findings, and we will then be able to see what route to take in this potentially MULTI forked path to success.
Your P.S. units . . . . . . .Selfie :
VISIBLE ADDENDA:
For Sir shrtrnd . . . .
No " exotic " adjunct sense terminal are incorporated on this unit.
ALSO . . . . there is no external current limiting control.
73's de Edd