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| Cursor jumps to back to home position. | Check U7 (6510 MPU) |
| Abnormal colors appear in the letters. | Check U6 (2114 RAM) U16 (4066 IC) |
| Different characters are displayed and cursor is locked when turned on and off. | Check RAM |
| System does not reset and the 'RESTORE' key does not work. | Check U20 (556 IC) |
| White band scrolls down the screen. (60 HZ HUM) | Check External Power Supply
VR2 (5V Regulator) |
| Cursor disappears after the system warms up. | Check U1 (6526 CIA) |
| SYNTAX ERROR displayed after system warms up. | Check RAM, U3 (ROM) |
| Wavy screen after the system warms up. | Check External power supply
U31 (74LS629 IC) U30 (74LS193 IC) |
| The system resets when it warms up. | Check U7 (6510 MPU)
U3 (ROM) |
| Keyboard does not operate correctly when the system warms up. | Check U1 (6526 CIA)
U3 (ROM) |
| Black band scrolls through screen when the system warms up. | Check External Power Supply
C90, C88, CR4 VR2 (5V Regulator) |
| Cassette motor keeps running. | Check U7 (6510 MPU) |
| Cassette motor keeps running even after a program is done loading. The TIP 29 transistor gets extremely hot and the fuse may possibly blow. | Check Cassette Port for Shorts
R4 (Possibly Open) |
| The cursor disappears when the cassette is plugged in. | Check U7 (6510 MPU) |
| Cassette runs extremely slow. The program seems to load but will not run. | Check U7 (6510 MPU) |
| This page has been created by Sami Rautiainen. | |
| Read the small print. | Last updated September 05, 2020. |