Ran through my SR-60 presentation with the wife last night; tweaked a few things. Fired up the SR-60 and loaded the "Threez" program, which calculates all three digit numbers equal to the sums of the cubes of their digits. (This takes a 15C LE about 10 seconds, total, and takes the SR-60 about 15-20 minutes. But at least it can print out each one!)
The program should print "THREEZ", then 153, 370, 371, 407, and then "DONE".
Came back about half an hour later and found it had printed up through "407" and was sitting there with no display. Turned it off and left it for an hour, but it still wouldn't turn back on.
Opened it up, reseated every socketed chip, sprayed display connector and cable with contact cleaner, turned it on again...PROMPTING DESIRED?
Verified operation of printer and card reader, etc.
Let's just hope it holds together over the next few days.
There's visible corrosion on the legs of some of the socketed ICs. This has happened once before; I suspect some chip or two is getting slightly warm and losing contact with its socket...but it's just a guess.
In any case I'll be bringing the tools I need to open it up, contact cleaner, and a wrist strap. 'cause you never know.