Ran it off a desktop power supply measured at 9.1V DC.
Screen reports 9.1V DC.
Ran through the self test using 100nF capacitor and a set of joined wires to short probes 1-2-3
A 33nf capacitor with this reported as 33.29nF which tallied with another tester.
Bit cold in workshop right now so will post a few more images of random junk box/salvaged components then pick this up another day but on face of it seems to be working fine.