Sep 212014
 

Another one of Ben’s boards.
Had the usual graphics issues you normally get associated with those four 2114 RAM’s only this time the RAM’s had already been replaced and all four were good.
IMAG0908

Following the inputs and outputs from these RAM chips I found some broken traces, probably a result of desoldering them originally.
Pin 1 of the RAM at location 3H was not connected to anything. I patched this and it fixed the solider sprite on the title screen but some in-game graphics were all messed up.
IMAG0909

IMAG0910

After confirming all other connections were good I noticed two other 2114 RAM chips that had been worked one and socketed so I checked those too.
Initially I found pins 3 and 4 of the RAM chip at 1B. Patching these gave me this result
IMAG0912

Getting there but not quite.
A little further inspecting these chips and I also found pin 15 of the same chip not connected to GND like it should be.
Patching this one gave me a perfectly working game.
IMAG0913

IMAG0914

  One Response to “Space Invasion repair log”

  1. You are a legend mate 🙂

    – Ben