If the votlage drops on load, the machine might not work correctly, but in general no damage will be done. It is rare, but possible [1] for the output of a regualtor to rise on load. It's therefore always safest to do a load test [2] but it's less importnat than chackign the PSU off-load in the first place. [1] The normal casue of this is an swithcing regulator -- the H744, for example, but not IIRC< the +15V supply in the BA11-K -- where hte output capacitor has got a high ESR. You can get some spikes on the output several times the correct outptu votlage,adn they get worse asnm the laod increases. I had a suppy in an HP device that would work fine off load but where the crowbar would trip as soon as you loaded it. A newer capcitor solved the problem, once I'd worked out what was going on. [2] Car bulbs are nominally 12V, but car electricak systems run at 13.8V or so when the engine is running. Such blubs should stand 15V for a short time -- long enough to test the supply. -tony