Voltage

Mac Terminal Interface Macintosh 128

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious personal injury or equipment damage, review CRT safety and discharge instructions in Bulletins Safety. Caution Because you must make voltage adjustments from the rear of the computer, use a mirror to view the computer screen. Do not reach around the computer to adjust the controls. Note You must verify voltages after you replace the logic board or the power sweep board. 1 Set the voltmeter to 20 V...

Logic Board Upgrade

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious personal injury or equipment damage, review CRT safety and discharge instructions in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. Note This kit cannot be installed unless the Floppy Drive Upgrade Kit has been installed. The Logic Board Upgrade Kit upgrades the logic board of a 51 2K Mac to a Mac Plus. The kit contains a new logic board with 1 MB of RAM,...

General

The Symptom Charts included in this chapter will help you diagnose specific symptoms related to your product. Because cures are listed on the charts in the order of most likely solution, try the first cure first. Verify whether or not the product continues to exhibit the symptom. If the symptom persists, try the next cure. Note If you have replaced a module, reinstall the original module before you proceed to the next cure. If you are not sure what the problem is, or if the Symptom Charts do...

Power Sweep Board

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious personal injury or equipment damage, review CRT safety and discharge instructions Bulletins Safety. Warning Never use a grounding wriststrap until after discharging the CRT. 1 Disconnect the following cable connectors from the power sweep board 2 Remove the screw and lockwasher that hold the ground wire to the chassis. 3 Note You may need to remove the insulating paper from the power sweep board to...

Tilt Adjustment

Note If glue holds the yoke collar in place, use an art knife to cut through the glue. 1 Loosen the yoke clamp screw two or three turns. 3 With one hand, grasp the plastic spokes of the yoke collar and rotate the yoke collar until the top and bottom edges of the picture are parallel with the top and bottom of the bezel. 4 Switch off and unplug the computer. Hold the plastic collar in position and slowly tighten the yoke clamp screw so that the collar cannot slip. 7 Replace the cover and switch...

Logic Board

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious personal injury or equipment damage, review CRT safety and discharge instructions in Bulletins Safety. Warning Never use a grounding wriststrap until after discharging the CRT. 1 Disconnect the following cable connectors from the logic board 2 Caution When removing the logic board, be careful not to damage the SIMMs especially the larger DIP SIMMs that may be installed on the board. Pull back on the...

Floppy Drive Upgrade

Awarning This product contains high voltage and a high-vacuum picture tube. To prevent serious personal injury or equipment damage, review CRT safety and discharge instructions in Bulletins Safety. Awarning Never use a grounding wriststrap until after discharging the CRT. Note This kit replaces the 400K floppy drive on a 51 2K Macintosh with an 800K floppy drive. The kit contains the new drive and two new ROMs for the logic board. The new ROMs support both the 400K and the 800K drives. This...