Obviously, it’s very dangerous to work on the innards of any line-powered electronic

equipment if the unit is still plugged in. So, before you do anything, UNPLUG IT. Don’t

rely on the on/off switch -- actually remove the power cord. Repeat: Pull out the cord.

Got that? Out with the cord. If you must work on the unit “hot” for some reason, please

pay attention in what follows to notes on how to reduce the risk of killing yourself. A com-

pact Mac by itself may be small, but your power company is very, very strong. Pull out

the cord. This warning brought to you by the Department of Redundancy Department.

Unless you are going to work on the HV circuitry, it’s best not to discharge the CRT, con-

trary to most written advice (including Apple’s). The reason is simple: You have to expose

yourself to the possibility of contact with HV to do so. If you make a mistake, you will

receive an unpleasant (but not lethal, despite what a lot of people say) shock. Or, the dis-

charge might take a path through delicate components and damage them. Since the HV

wiring is very well insulated, you will be well protected if you simply leave it alone.

To reduce the risk of getting shocked, let the unit sit unplugged for a day or two. If the

Mac is healthy enough to light up the screen, you can speed up the process by turning up

the brightness, and then unplugging the Mac while it’s still powered on (yes, this is a little

rough on disk drives, so make certain that no disk activity is happening). The current

drawn from the HV supply by the still-functioning circuit will rapidly discharge the HV.

2.2 Opening up the Mac

You’ll need a very long mutant Torx-15 driver to open up a compact Mac. Two screws are

in the deep recess along the top, and another two are on the back panel, straddling the con-

nector array on the bottom. For the 128K, 512K and Plus, there’s also a fifth screw, hidden

inside the battery compartment.

Once all the screws are out, hold the Mac with the CRT facing down, a couple of inches

over a soft surface (carpet is good). Holding the unit by the rear cover alone, give it a vig-

orous shaking until the cover works loose from the rest of the unit. The two case halves

can be very tightly joined, so expect a little bit of a struggle. Just be patient.

Don’t use a screwdriver, or you’ll chew up the case. Special “case crackers” exist, but I

find that the “shake it until the front falls out” method works fine.

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