Below are common issues with the ColecoVision and their solutions.
Garbled Graphics
See the dedicated Garbled Graphics Fix page.
Officially-documented Issues
The following fixes are documented in the [[File:ColecoVision_Technical_Manual.pdf|ColecoVision Technical Manual]:
- Black out on screen
- If the screen blacks out after the game has been played for a short interval, check C106 for proper polarity. If polarity is wrong, replace C106
- Purple Monkey
- In Donkey Kong, if the monkey, Mario, and the barrels are purple, rather than their normal colors, replace U9
- Joystick Game Selection
- If the keypad does not control the game selection, only the joystick can be used to select games, replace U6 (also see Common Problems section above)
- Channel 3 [works] but not 4
- Channel 3 operates normally but channel 4 only works if the game is turned off and then turned back on again, (or vise versa) replace RF board.
- Not all cartridges function
- Game does not accept all and/or any cartridges. Examine C70 for mechanical obstructions. Is it flopped over flat on board? Replace U5.
- Vertical lines
- Vertical lines on background rather than solid blue background with no lines. Replace C106.
- Skips menu
- Menu is skipped. This is the blue screen with skill levels. Check pins 3-9 of U18 with DVM. If any pin is below 2.2VDC change U18. Check pins 2-8 of U19 with DVM. If any pin is below 2.2VDC change U19.
- No explosion
- If there is no explosion, a sound testing of the noise generator, on the final test, replace U20.
- 12 VDC is shorted to -5 VDC
- Examine WJ2 to see if it has shorted to adjacent test points.
- No RF voltage
- If there is no voltage on the RF board, check WJ2.
- No Color
- If color has disappeared, check frequency at J4 pin 6. Correct frequency is 3.57954 Mhz +/- 100 Hz. If the frequency is incorrect, check the clock circuit.
- Double images
- Replace U9 for double images.
- Wavey (sic) picture
- If picture is wavy, ensure that R62 is 270Ω and C90 is 120pF. If they are incorrect, replace them. Check Q2, if it is an ITT transistor, replace it.
- Incorrect scoring
- If scoring is not working properly, replace U3 and/or U4.
- Wrong frequency
- 3.579 Mhz clock is the wrong frequency. If U22 is a Texas Instruments IC, replace it.
- Bad spinner interface
- Spinner interface is not working. If U24 is a Texas Instruments IC, replace it.
- Slow game
- If game is running abnormally slow, replace U20.