desoldered System-Austria rape harness from jamma connector.

 

sanded the jamma connector.

 

First playtest resulted in garbeled sprites and backgrounds. No background music (missing -5V).

100_5337

 

Reseated all roms. That brought back all graphics.

 

Coin entry did not work.

 

Traced coin switch to an IC-leg, that was surely cut on purpose.

pcb_dd_pin

Resoldered that leg back to the IC.

 

Now stuck at boot-up. sometimes displaying a „2“ or „99“ at the bottom.

 

Measured Volts. Board got just above 4.6 Volts. even at the last corner. Pretty low.

 

cleaned back of bottom layer. Used soda-cleaner and lighter-fluid. was dirty, now it shines – mostly.100_5327

 

looked for broken traces. found a cut and resoldered multiplexer. Not sure if I can repair that one.

100_5321

still stuck. wtf? Whats wrong?

 

reseated all roms again.

 

still stuck. sometimes displays a „2“ at the bottom. Maybe because Coin-switch activates all the time.

 

desoldered the pin I connected. Now it booted, but with the distorted sprites back again. I already had that seen better.

100_5332

Used screwdriver to connect coin-switch manually. Gave out credits instantly. All controls normal. I am very sure now, that the credit-circuit was destroyed on purpose.

 

Will have to reseat the roms again.

 

Connected 74LS139 legs. Did not change the sprites. Connecting the Coin trace gives out credits, and while connected, it pauses – explaining why it got stuck at bootup.