Apple Macintosh PowerBook 190 Series - Manual (Page 112)

Problems with equipment connected to your Macintosh PowerBook
If a problem occurs while your Macintosh PowerBook is connected to
external equipment, such as SCSI equipment, an external monitor, a modem,
a printer, a mouse, or an external keyboard, these steps may help you
determine the source of the trouble:
1 Shut down your Macintosh PowerBook and anything that’s connected to it. Disconnect
everything connected to your Macintosh PowerBook (except the power adapter) and
restart it.
Note: If you’re connected to a network, contact your network administrator or
warn other users before disconnecting from the network, because it may
interrupt network services.
If the problem does not recur, it is likely to be related to equipment connected
to your PowerBook.
2 Shut down the Macintosh PowerBook.
3 Reconnect one device.
4 Make sure that the device is plugged into a working outlet and turned on, if applicable.
5 Start up the Macintosh PowerBook.
6 Repeat steps 2–5 until the problem recurs. The last device you connected may be
causing the problem.
105 Tips and Troubleshooting