Smoke From PSU Socket

Samll incandescent filament bulbs. I thought I'd mentioend this before. It was a bulb with a difficult-to-find cap, so I broke the old glass (containing the burnt-out filamanet) out of the cap, cleaned up the latter, and soldered a wire-ended bulb of the right rating to it. Given that it was useless anyway, I think I would have tried cutting the end off the filter section. You migth have been able to extract the defective components and wire in standard filter module (thus keeoign the votlage selector feature of the original). I have come across these units on some HP devices. The Thinkjet printer and the HP9817 computer spring to mind. There are several versions of the camshaft, one just operates one of the contacts fopr 115V/230V switching of an SMPSU, the other operates all the contacts for configuring a 0-120 and 0-100-120 priamry mains transformer for 100V, 120V, 220V and 240V. The Thinkjet does that, and the service manual doesn't explain it (the one on my shelf has an extra sheet in it now giving the wiring..) -tony