Without further information, many people assume that they need a whole new hard drive. Rather than spend the money, they shelve the computer. Well, it's time to dust it off! Error code 81 simply means the brake is out of adjustment. You can fix it, easily, in under an hour, with a #1 Phillips- head screwdriver and a .012-inch feeler gauge. Here's the complete procedure:

1. Disconnect the computer's power cord from the wall outlet.
2. Remove the disk-drive cage as shown in Figures 1 to 3.
3. Disconnect all data and power cables from the installed drives.
4. Turn the cage upside down. This puts the relatively light disk drive on top and the relatively heavy hard drive on the bottom.

Figure 25 Four screws hold the sheet metal support bracket.

5. Use a #1 Phillips-head screwdriver to remove six screws (three on each side of the cage) which hold the hard drive in place.
6. Lift the drive cage straight up. This leaves the hard drive upside down on the table.
7. Use a #2 Phillips-head screwdriver to remove four screws from the sheet metal support bracket as shown in Figure 25. Lift the bracket away and put it aside.
8. Locate the solenoid marked "Inertia Dynamics, Collinsville, CT USA." Insert a 0.012-inch feeler gauge as shown in Figure 26.

Tighten the screw, reverse steps 7 through 1, and everything should be OKI If not, repeat steps 1 through 9, allowing a little more or a little less clearance, until you get the brake working.

Figure 26 Adjust the brake with a 0.012-inch feeler gauge.

9. At the time of failure, clearance might be as much as 0.075 inch. Loosen the solenoid holding screw and adjust for 0.012-inch clearance.