Lady Bug

In normal mode, just had a blank screen. Enable test mode and you instead get an error message showing that the ROM test had failed (even though the rom itself checks out OK with correct content) This is because the custom Atari SLAPSTIC chip is not functioning correctly. It is used to page banks of…

Crashing game. Game woud start attract mode, but shortly after would crash and boot loop. Entering test mode (hold player 1 start button whilst switching on) and it would pass first time around, but fail at random addresses on subsequent runs. The /WAIT signal on the main Z80 is handled by the IC at E2…

I had a spare bootleg replacement play pack from a Driving force on Galaxian hardware, so I proceeded to trace the circuit and try to identify the ICs used since they all have the IDs removed, other that the one attached as a later addition as IC7. Following the tracing, I used the pinouts to…

Glitched graphics. Screen changes as board is flexed. Moved around board pressing chips until pressing the custom surface mount chip at B6 changed the effect. Noticed that the corner most pins had come up from the board. After an unsuccessful effort to resolder them, I used some enameled 38 swg wire to solder from the…

6 Slot – Memory test on power up giving error  Address    Write Read  00008000 5555 55FF Checking with Mame, the memory chips in question were only small, so looking at the board revealed two DIL 5814’s. Chip select signals to these were toggling as expected, so I needed to identify which ram chip was which….

Capacitor burnt. (game board), particularly at C37 the capacitor was showing signs of extreme heat. Replaced them all with 22uF 25V axial electrolytics. No Speech / Some SFX missing. (game board) Output from speech chip SC01 was OK, as was output from IO Custom (X3). checked transistors in output stage and 2N4401 was faulty. (Q2)…