Printer help?

Well, while my IIISi is a long way from being _totally_ taken apart, I've done a good deal with it. :) I believe your guess is correct. Actually, so does the IIISi - once you know how. But it's more like half an hour to 45 minutes if you have no reference and no experience. Anyway, I believe I've now found the offending bit. By the time I got it down to the point where anything more would mean some pretty major mechanical work - I'd pulled apart all the obviously-accessible electronics, and anything more is either more electrical than electronic (eg, motors) or very delicate stuff I am not about to mess with (eg, the driver circuitry for the laser) - by the time I reached this point, I'd failed to find anything obviously fried. So I put it back together but with one side tipped down, in the hope I could see something. It's possible to reassemble it electronically without completely reassembling it physically - in particular, it's possible to have most of the electronics in view. I then turned it on. Power came on and I saw some very brief visual event - looked like a flash of light, but as I wasn't foveating on it I couldn't really be certain - from a place where there is no component designed to do anything visually detectible. There was a small tick, and power went off again. A moment later power came back and I saw a wisp of smoke curling up from about where I saw the flash of light; it then blinked out again. Thus, I believe you are correct that the power supply was sensing overload and cutting out, repeatedly. Power off immediately, of course. Then I extracted the relevant PCB and inspected that spot closely. It appears that an electrolytic cap has sprayed some black substance out (which fortunately is not much - just another similar cap and some incoming wires). The cap appears otherwise undamaged to an in-situ visual inspection, but it's fairly obvious to me that it is Not Healthy. Fortunately, it's mounted through-hole rather than a surface-mount (while I'm willing to believe the list that surface-mount components are replaceable, I do not want something like this to be my learning experience on the subject!). Also fortunately, it's a common-as-dirt value (220?F 35V), though since it appears to be a power decoupling cap, the exact value is probably not critical. I doubt I will have the leisure to replace it anytime soon, though, even though it means my printer will be down; the next couple of weeks, at least, are looking..busy. /~\ The ASCII der Mouse \ / Ribbon Campaign X Against HTML mouse(a)rodents.montreal.qc.ca / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B