The information about these machines was at least partially incorrect, and that’s a good thing. All three units did in fact power up, though none of them were completely successful. The first Apple III I plugged in, serial #051780, showed some good signs of life with both the keyboard power lamp and the internal LED (CR7) lit up.
The floppy LED didn’t blink and I didn’t get any video output, though. The attempt to reach the MONITOR prompt returned a screen full of flashing garbage graphics. Not a good sign.
Power light - 051780
The second system (050756) also responded with warmly glowing power lights, and again, no video. This time, I got no response when I tried to invoke the diagnostic. Gently wiggling the cable to the composite monitor gave brief flashes of static on the screen and little else. Perhaps a failed video ROM? Again, no drive activity was seen. My sense of impending doom was growing.
ROM test - 051780
The final III, oldest of the trio (serial #018052), is also the one to have best weathered the ravages of time. All keycaps are present on the keyboard, and it’s got the least build up of dust, dirt and what appear to be wood shavings. On the other hand, several of the keys became the final resting place of partially digested worms and whatever else bird eat and then poop out (see below).
Fingers crossed, I hit the power switch and said a little prayer to the silicon gods. This machine got furthest of all, reaching a flashing cursor prompt (always a good sign) under the word RETRY. According to this article, this may in fact be expected behavior. The diagnostic appears to complete without error, and a CTRL-RESET got me to the MONITOR prompt. Still no drive activity, however.
So now, it’s time to dig into the plethora of Apple III literature available around these nets and maybe learn a thing or two. If all this takes is a new internal floppy mechanism and a dose of Retrobrite, I’ll be a happy computist.
RETRY - 018052
I have a few ///s also – where did you find the diagnostic disk?
Thanks!
You can download the Apple III Dealer Diagnostic disk image at http://apple3.org, along with a wealth of other information, manuals and images.
I have a ///, and my situation is the same is the last (although I’m positive that my media degenerated)
What I would recommend with the first two is to pick them about 3 inches from the floor, and slam the computer down to reseat the chips. Trust me, it’s better than taking all of the boards out, and pushing on the chips located on the motherboard.
@Camden: Ah, the infamous Apple /// dropfix! I went ahead and manually reseated each of the chips, with no luck. I fear I may be forced to pull out the multimeter and logic probe if I want to pursue this any further…
@Mike: Have you been able to locate the board that has the problem? And on #018052, Have you tried ADTPro and a Serial Null Modem Cable to make some disks to try? You can also check the disk drive speed, and analog board and some other things that I never did, so I can’t remember (Using the /// confidence diagnostics)
@Camden: I haven’t nailed it down yet. I did swap the power supply for a known good one and got the same results, so there’s probably something on the logic board that is pulling it down. Board swapping is an easy, if scatter-gun approach and doesn’t always reveal the real problem, unfortunately. Like I said, I think the next step is probably a multimeter and logic probe.
On #018052, I can successfully transfer disk images directly to the /// using ADTPro. The drive passes all the diagnostic tests on the Dealer Diagnostics Disk and Confidence Disk, so I’m assuming that the drive needs to be aligned, a process I’m not familiar with. Or, maybe there’s a flaky chip on the motherboard that causes the crashes when I try to boot certain disks (like the Demo Disk).
@Mike: I’m in the process of getting some new AC main filter capacitors for the power supply, but while mine was down, I cleaned the head (it was covered in dust & dirt from it’s incarceration), and I was going to align it, but I’m not sure about the process, either.
I do know someone who had to use a multimeter and a logic probe (luckily not me, because that stuff is a pain), but it (I don’t know if it’s any help, but it might be the same chip) turned out that the bad chip was number 341-0042. But, that chips is for a 12 volt board…