I am a Mac user since about 1990. I remember compact Macs being very popular with the staff in college: It provided an easy to use standard GUI, desktop publishing, and campus wide networking, that was unmatched by PCs until latter in the 90's. Back then I had a 2nd hand Mac II, later I got a Powerbook 165c.
I generally don't recommend buying old Macintoshes from the late 80s and early 90s, because they are often very damaged with battery and capacitor corrosion.
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| First run. |
But last Fall I saw a Macintosh Classic listed as broken and very cheap. One of the pics in the listing shows the video working and the desktop, so, it there is any problem with the computer, it is probably something minor.
A corner of another picture showed the included mouse and an upside down keyboard. The keyboard was an Apple Desktop Bus Keyboard originally sold with the Apple IIgs. This is my favorite Mac keyboard, and alone costs as much as the listing, and maybe 3 times more if it is the version with Alps switches. The space bar seemed of a yellower shade than the other keys, this is a characteristic of Alps keyboards so chances were high that it was the better one.
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| Keyboard with orange Alps mechanical switches. The space bar and case are ABS plastic that yellows with age. The other keys are PTB plastic. The keys share the early snow white design language used in the Apple IIc keyboard. |
I got the Mac Classic, it is surprisingly smaller than what I remember, and, YES! the keyboard is indeed the "made in Japan" version with Alps switches! However, one of the keys broke during shipping. This is not a big deal as it can be glued.
Fixing the Keyboard
To fix the key I first removed the key stem that was stuck to the switch using a very small drill bit (a very small screw also works). I then carefully super-glued it back to the key, using metal wires (trimmed resistors or capacitor leads) to line up the stem and to reinforce the connection. I let the glue cure for 24-hours. Finally, I trimmed the metal leads flush, and I installed the key.
Fixing the Computer
Unfortunately, there was nothing to fix as the computer started with no problem and there were no signs of faults. Even the SCSI hard drive was working. I disassembled it, and the logic board looked very nice, no visible corrosion or capacitor leakage. I removed the lithium clock battery to prevent future corrosion.
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| Logic board and Ram daughter board. No leakage around the lithium battery. |
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| Extreme care is necessary when servicing a compact Mac. There are high voltages that can kill you. Remember to properly discharge the CRT and power capacitors. |
A few months latter, it stopped booting, showing instead the following sad mac screen on startup. The error code points to memory problems.
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| Sad mac boot screen. |
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| Mystery goo on the SIMMs and connector. |
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| Booting after washing the goo and drying the board. |
Replacing Capacitors
A month latter, after replacing the capacitors in a broken Mac Classic II, I decided it was time to recap this Mac Classic logic board too. It was a good idea, as I saw signs of dried leakage under some electrolytic capacitors.
I do have most of the SMD electrolytic capacitors required, but I decided to use thru hole capacitors instead because they are much easier to solder, and there is sufficient space to lay then horizontally on the board to secure then properly.
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| Recapped logic board with thru-hole capacitors mounted horizontally. I added a drop of hot glue to further secure each capacitor in place. |
Resources
- Check out these Adrian's Digital Basement videos to see what to expect when fixing old compact Macs.
- Mac Classic II Service Source.
- Sad Mac Error Codes.
- Repair Mac SE/30.
- Troubleshooting_Your_Macintosh_1992.
- Macintosh Upgrade and Repair Secrets.
- The Dead Mac Scrolls 1992.
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