Logic Board's Pin assignments of LC520/575 for External Monitor
| Number | Signal of Logic board |
Processing |
| 1 | -12V |
Cut |
| 2 | GND | |
| 3 | +5V | Cut |
| 4 | GND | |
| 5 | +5V cont. | connect to #7, Cut |
| 6 | GND | |
| 7 | /PFW | connect to #5, Cut |
| 8 | GND | |
| 9 | Composite/Horizontal sync. | XNOR output |
| 10 | GND | GND |
| 11 | Video (B) | Blue, Cut |
| 12 | GND | |
| 13 | Video (G) | Green, Cut |
| 14 | GND | |
| 15 | Video (R) | Red, Cut |
| 16 | GND | |
| 17 | Brightness | 0-5V |
| 18 | GND | |
| 19 | Contrast | 0-5V |
| 20 | Monitor ID 2 | |
| 21 | Mic (+) | |
| 22 | Mic (-) | |
| 23 | +5V | |
| 24 | Monitor ID 1 | |
| 25 | Monitor ID 0 | |
| 26 | GND | |
| 27 | n.c. | |
| 28 | Sound out (R+) | |
| 29 | Sound out (R-) --> FG | |
| 30 | Sound out (L+) | |
| 31 | Sound out (L-) --> FG | |
| 32 | GND | |
| 33 | Vertical sync. | |
| 34 | n.c. | |
| 35 | n.c. | |
| 36 | GND | |
| 37 | Sound muting control | |
| 38 | GND | |
| 39 | Monitor blinking control | |
| 40 | GND | |
| 41 | n.c. | |
| 42 | n.c. | |
| 43 | n.c. | |
| 44 | CD-ROM sound (R+) | |
| 45 | GND | |
| 46 | CD-ROM sound (R-) | |
| 47 | GND | |
| 48 | CD-ROM sound (L+) | |
| 49 | GND | |
| 50 | CD-ROM sound (L-) |