Commodore 64C - Troubleshooting Common Issues

troubleshooting chart
Symptom
Cause Remedy
Indicator light not 'ON"
No picture (Monitor)
No picture (TV)
Randc
Pictun
Sound
■■:
■.■■.;
pattern on screen wit]
ith po. ,r or no color
th excess background
i cartridge in
noise
pi net1
Picture OK, but no sound
Sound OK, but no picture
Computer "locked" (cursor not flashing)
Computer not turned ON
Power supply not plugged into computer
Power supply not plugged into external power
Bad fuse
Monitor not connected and/or not turned on
Im orreci hookup
TV not connected and/or turned on
Cable toTV not plugged in
Computer and/or TV set for wrong channel
Cartridge not properly inserted
Poorly tuned color controls
Volume too high
Volume too low
Audio input ol monitor audio/video cable not
i nnne< ted
[f using external amplifier, connections or settings
not correct
See "No picture" listings above
C Computer inadvertently received instructions to
disable keyboard; or the printer, cassette or disk drive
is in listening mode
Computer displays garbled symbols on the screen Overheating
Make sure power switt h is in ON' position
I lux k power socket for loose or disconnected power
cable
Check connection with wall outlet
Replace fuse
Check monitor conne< t ions and/or
ON/PIT switch
Check computer hookup to VHFantenna terminal;
Check TV power connection and ON/OFF switch
Check output cable connection to TV
Set computer to same channel :>s TV 0 ur 4)
Turn power OFF and reinsert cartridge
Adjust color controls on TV nr monitor
Adjust volume
Adjust volume
( Connect audio cable io monitor audio input
Connect sound jack to AUX input on amplifier and
selet i AUX input
Sec "No picture" listings above
While depressing ilu-RlN ^TOPkcy
press RESTORE key twice; or reset the peripherals by
turning off and on; or turn the computer off and on
Pull plug on power supply and allow to cool down
(make sure ;iir flow around power supply is not
restricted)
NOTE: Stati< electrii ity generated by walking on rugs or carpeting can damage computer equipment. If such
conditions exist, he sure tndist harge the static electricity by touching ;i metal objci t before touching! he computer or
other equipment.
Also, power surges can damage computer equipment or cause data to he lost or garbled. You can avoid this by
installing an inexpensive surge protection device, available at your local electronics or hardware store.
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