Commodore 64 User Manual page 67

TROUBLESHOOTING GUIDE
PROBLEM POSSIBLE CAUSE REMEDY
Power light off Computer not turned on
Computer not properly
connected to power supply
Power supply not properly
connected to wall
Blown fuse in building
Blown fuse in computer
Power light on, but no picture TV on wrong channel
(after second attempt to turn
on computer) Incorrect hookup at TV
Modulator does not work
Poor picture
Picture with poor color
Picture with no sound
[if using a program with
sound)
Picture with poor sound
[if using a program with
sound]
VIC modulator or monitor
cable not plugged in
64 video cable not plugged in
at computer
Modulator on wrong channel
TV not turned on
TV not tuned well
Bad color adjustment on TV
Bad color adjustment on
computer
TV volume too low
TV fine-tuning off
TV volume too high
Interference from other
devices
Turn on power switch at side
of computer
Check power socket at side
of computer
Check wall outlet
Check fuse box
Have dealer replace with
3 amp slo-blo fuse
Try both Channels 3 & 4
Hook up to VHF antenna
terminals
Check cable connection at
TV/game switch box
Check five-pin DIN connector
on back of computer
Check cable connections at
back of computer
Flip switch on modulator or
on back of 64
Turn on TV
Check fine tuning of channel
on TV
Adjust color, hue, and
brightness controls on TV
Have dealer adjust computer
Adjust TV volume
Check fine-tuning of channel
on TV
Adjust TV volume
Turn off other nearby
electronic devices
65