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See the original scan and C64 motherboard layout at the bottom of this page |
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Commodore Diagnostician II By Ian Perry, Kyneton, Victoria 3444, Australia Sept 1989 Symptomatic Chart Diagnosing Faulty IC Components On |
6510 Proc | 6526 Complex Interface ADP | 6581 Sound Interface Device | 6567 VIC NTSC (6569 PAL) | 82S100 Prog Logic Array | 901226 Basic ROM | 901227 Kernal ROM’ | 901225 Char ROM | 8701 IC Clock Gen | 2114 Color RAM | 4164 Memory RAM | Power Supply |
| Cursor jumps back to home position | x | x | ||||||||||
| Abnormal colors appear in the letters | x | x | ||||||||||
| Different characters are displayed, cursor is locked when turned on & off | x | x | x | |||||||||
| The ‘RESTORE’ key does not work | x | x | ||||||||||
| Cursor stops blinking when system warms up | x | |||||||||||
| Keyboard does not operate correctly when system warms up | x | x | x | |||||||||
| Syntax error | x | x | ||||||||||
| Cursor disappears when cassette is plugged in | x | |||||||||||
| Cassette runs extremely slow, the program see,ms to load but will not run | x | |||||||||||
| Blank screen on power up | x | x | x | x | x | x | x | |||||
| Intermittent blank screen or graphics | x | x | x | x | x | |||||||
| Powers up when ‘PRESS PLAY ON TAPE’ message and the display blinks | x | x | ||||||||||
| When ‘RETURN’ is pressed after a run command, cursor returns to home position | x | x | x | x | x | |||||||
| Poke command does not work | x | |||||||||||
| Joystick does not operate correctly | x | |||||||||||
| Unreadable letters appear on screen | x | x | ||||||||||
| Keyboard is unresponsive | x | |||||||||||
| Graphic characters instead of letters are displayed | x | x | x | |||||||||
| ‘DEVICE NOT PRESENT’ error is displayed, when disk is used | x | x | ||||||||||
| Disk drive continues to search when trying to load | x | x | ||||||||||
| Inconect screen color or no color at all | x | x | x | |||||||||
| Cassette does not save | x | |||||||||||
| Flashing colors or blocks | x | x | ||||||||||
| Game cartridge does not function | x | x | ||||||||||
| User port doeS not function (eg. modem) | x | |||||||||||
| No sound | x | |||||||||||
| Missing notes | x | |||||||||||
| Game paddles do not function | x | |||||||||||
| Long programs do not lOad | x | x | x | |||||||||
| Unit completely dead (30 – 40% possibility PLA) | x | x | x | x | x | x | ||||||
| Wavy screen after system warms up | x | |||||||||||
| ‘OUT OF MEMORY’ error on power up | x | |||||||||||
| After a few minutes, characters all over screen | x | x | x | x | ||||||||
