Apple quadra 840av 服务手册

 

 Troubleshooting

Symptom Charts/Peripherals

 

 (Continued)

 

 - 15

 

Double-click doesn’t 

open selected item

1 Remove duplicate system folders.

2 Clear parameter RAM. Hold down <Command> <Option> <P> 

<R> during startup but before “Welcome To Macintosh” 

appears.

3 If mouse was connected to keyboard, connect mouse to 

computer ADB port instead. If mouse works, replace 

keyboard.

4 If mouse does not work in any ADB port on computer, replace 

mouse.

5 Replace logic board. Retain customer’s SIMMs.

No response to any 

key on keyboard

1 Check keyboard connection to ADB port.

2 Replace keyboard cable.

3 Replace keyboard.

4 Replace logic board. Retain customer’s SIMMs.