IBM 704 - Manual (Page 265)

Troubleshooting
Monitor Problems Action
Wavy, unreadable,
rolling, distorted screen,
or screen jitter. If the monitor self-tests show that the monitor is OK,
consider the location of the monitor. Magnetic fields
around other devices (such as transformers, appliances,
fluorescent lights, and other monitors) can cause screen
jitter or wavy, unreadable, rolling, or distorted screen
images. If this happens, turn off the monitor. (Moving
a color monitor while it is turned on might cause
screen discoloration.) Then move the device and the
monitor at least 305 mm (12 in.) apart. Turn on the
monitor.
Notes:
1. The distance between monitors and diskette
drives should be at least 76 mm (3 in.) to
prevent diskette drive read/write errors.
2. Non-IBM monitor cables might cause
unpredictable problems.
3. An enhanced monitor cable with additional
shielding is available for the 9521 and 9527
monitors. See your IBM reseller or IBM
marketing representative for information
about the enhanced monitor cable.
If the problem recurs, have the monitor and system
serviced.
The monitor works when
you turn on the system,
but goes blank when you
start some application
programs. Verify that the primary monitor cable is connected to
the video port.
Be sure you installed the necessary drivers for the
application.
Blank screen Verify that:
1. The voltage-selection switch is set to the correct
setting.
2. The system power cord is plugged into the system
and a working electrical outlet.
3. The monitor is turned on and the Brightness and
Contrast controls are adjusted correctly.
4. The monitor signal cable is connected to the correct
connector on the system.
If the items above are correct and the screen remains
blank, have the system serviced.
Only the cursor appears. Have the system serviced.
Wrong characters appear
on the screen. Have the system serviced.
Chapter 5. Solving Problems 247