All, The result: Replacing the electrolytic capacitor on the lower leg of the voltage divider feeding the reset comparator did the trick. The system is now up and running normally (but I've forgotten the password! Hope I wrote it down, else I'll have to re-build the system...). Many thanks to Tony D. (who guessed right the first time), Toth, Peter, Antonio, and anyone else I've forgotten. Sorry it took so long to report - I just this morning got my friend at work to put the new capacitor in place. I still have the presumed leaky capacitor he took out, but have not tested it. Details of the problem are (presumably) in the archives; in brief, the primary symptom is that the system won't come out of reset (the code LED's on the back won't start flashing) on power-up, or falls back into reset peridically while running. Anyone with similar problems, I'll be happy to relate my full story and send pictures if desired. I *love* being on this list! Thanks again to all! - Mark