LaserActive:PAC-S10 - Various Issues and Solutions
This page details several faults discovered while servicing various PAC-S10/S1 modules and their solutions.
Post-Recap Short Circuit Check
After performing any capacitor replacement work, it is imperative to check the three voltage rails (+5, +8, -8) for short circuits. If there is a short circuit on any of these rails, it will damage the CLD-A100 player. Both the MAIN and SUB boards have fuses that are labeled with the voltages they protect on the back side of each board. Check that these are not shorted to Ground on BOTH boards. Also note that the SUB board has two grounds - one for digital and one for audio. The fused 5V rail is referenced to the digital ground and can be checked by measuring continuity to the ground on C506.
Fuse locations on the PAC-S10 MAIN board
Fuse locations on the PAC-S10 SUB board
Blank Screen on Power Up - Cartridges and BIOS do not load
Assuming no short circuits were measured across any voltage rail on the PAC, one root cause for this issue is the "D15" signal (IC1, Pin 32) being severed. This trace runs directly under C302, which has likely corroded the trace after years of being exposed to electrolytic fluid.
Restore the signal by reconnecting Pin 32 to the plated via next to the "40" text, adjacent to the BIOS EEPROM.
D15 Signal from IC1 (68000 CPU) damaged from electrolytic fluid corrosion
D15 Signal from IC1 repaired by connecting to an adjacent via
Missing/No Sound In Certain Games, Cannot boot Master System games
This is due to a missing data line from the Z80 CPU to the Sega 315-5660 ASIC. C129 is near the lines for D13-15 vias from the Z80 to the 5660 and C111 is near D5-7, increasing the probability of damage from extended exposure to leaked electrolytic fluid. First discover where the signal is lost and then jump the signal to the appropriate trace.
Z80 D14 signal restored to 315-5660 ASIC
Z80 D6 signal restored to 315-5660 ASIC
