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If a power supply needs a dummy load to work properly, or to be run without damage, it needs that load even if you're not checking that output. So yes, you have to have load resistors on all the outputs. I think the 'B' outputs are ones from the optional battery backup unit. On most DEC macnhines if you don't have the battery abckup unit, the 'B' outputs are totally dead, and are strapped to the apporpriate 'normal' PSU rails on the backplane. I would check the schematics of the PSU, though. Right... 10K is far too large. You want to draw aa significant current from the PSU outputs, that's the point of the dummy load. I would say perhaps 1-2A (or maybe more) from the 5V output and at least 0.5A from the +15V and -15V outputs. Let's consdier the 5V output first. To draw 2A, you need a 2.5 Ohm (not k) resistor. R=V/I and all that :-). Also note that it will be dispating 5*2 = 10W as heat, so a small resisotr is not going to do it. One of the easiest things to sue for this are low voltage filament lamps 12V car bulbs (say a 12V 5W taillight bulb) is fine for a 12V supply. And probalby fine for a 15V supply too (yes, the bulb will have a short life at the higher voltage, but not so short as to worry you). For the 5V line, a 6V bulb is the best thing to use, many older cars had 6V electrics nad you may well be able to get a 6V 30W bulb (which will draw around 5A) from a vintage car parts company. I bought a couple of headlight bulbs (each with a apr of 30W or so filaments and a couple of stop/taillight bulbs (5W and 21W filamnets). That gives me a good selection of laod currents (and yes, I once parallel to two filaments of a headleam bubl to give a load drawing somewhat more than 10A to test a large SMPSU). In amny DEC machines, the fans run off the mains input to the power supply (possible via an autotransformer or equivelnet for 230V mains). They don't count as a PSU load at all. -tony