On 6/2/07, g-wright at att.net <g-wright at att.net> wrote: Does the rear panel look like the diagram on page VIII-19 of this manual? http://www.bitsavers.org/pdf/hp/1000/1000_MEF_EngrRef/ 92851-90001_Mar81_9.pdf If so, most likely need to figure out what needs to be connected to the rear plug which is connected to the 02108-60032 control cable assembly shown on pages VIII-20 - 22. It sounds like the power supply could be in the CPU-MEM Alarm mode mentioned in this manual: http://www.bitsavers.org/pdf/hp/1000/1000_MEF_EngrRef/ 92851-90001_Mar81_8.pdf I haven't looked at that manual enough to see how the rear panel control cable assembly is wired in the power supply schematics or if the text describes what needs to be connected there for the supply to operate normally. That's where I would start with these manuals, unless someone else with direct knowledge can jump in with the answer on how to get the 2105A supply turned on in a normal operation mode. -Glen