On 7/13/2020 2:00 PM, Mike Stein wrote: > Shouldn't be too difficult to troubleshoot; have you got the manual? > > Start by checking the 24V > 12V regulator... As for a manual, I have this: https://www.scss.tcd.ie/SCSSTreasuresCatalog/hardware/TCD-SCSS-T.20141115.002/Tandon-TM848-Specification-and-Schematic.pdf I don't see the VR section in that, though.