| Число сигналов | Проблема | Решение |
| 1-1-3 | Real-time clock write/read failure | |
| 1-1-4 | ROM BIOS checksum failure | |
| 1-2-1 | Programmable Interval Timer failure | |
| 1-2-2 | DMA initialization failure | |
| 1-2-3 | DMA page register write/read failure | |
| 1-3-1 | RAM refreash verification failure | |
| 1-3-3 | 1st 64 KB RAM chip or data line failure multi-bit | |
| 1-3-4 | 1st 64 KB RAM odd/even logic failure | |
| 1-4-1 | 1st 64 KB RAM address line failure | |
| 1-4-2 | 1st 64 KB RAM parity test in progress or failure | |
| 2-1-1 | Bit 0 1st 64 KB RAM failure | |
| 2-1-2 | Bit 1 1st 64 KB RAM failure | |
| 2-1-3 | Bit 2 1st 64 KB RAM failure | |
| 2-1-4 | Bit 3 1st 64 KB RAM failure | |
| 2-2-1 | Bit 4 1st 64 KB RAM failure | |
| 2-2-2 | Bit 5 1st 64 KB RAM failure | |
| 2-2-3 | Bit 6 1st 64 KB RAM failure | |
| 2-3-4 | Bit 7 1st 64 KB RAM failure | |
| 2-3-1 | Bit 8 1st 64 KB RAM failure | |
| 2-3-2 | Bit 9 1st 64 KB RAM failure | |
| 2-3-3 | Bit A 1st 64 KB RAM failure | |
| 2-2-4 | Bit B 1st 64 KB RAM failure | |
| 2-4-1 | Bit C 1st 64 KB RAM failure | |
| 2-4-2 | Bit D 1st 64 KB RAM failure | |
| 2-4-3 | Bit E 1st 64 KB RAM failure | |
| 2-4-4 | Bit F 1st 64 KB RAM failure | |
| 3-1-1 | Slave DMA register failure | |
| 3-1-2 | Master DMA register failure | |
| 3-1-3 | Master interrupt mask register failure | |
| 3-1-4 | Slave interrupt mask register failure | |
| 3-2-4 | Keyboard controller test failure | |
| 3-3-4 | Screen memory test failure | |
| 3-4-1 | Screen initialization failure | |
| 3-4-2 | Screen retrace test failure | |