The Williams Flash I've been working has each row of column 3 acting up (each switch will activate various things all at one time). After checking the diodes on the playfield as good, I was about to go into diagnostics mode switch test and jumper the chip to see what was being activated but I can't get into diagnostics mode.

I'll get to the part where all the displays go blank after pressing "advance" with the switch at "manual down" on the coin door, then, when I switch it to "up" and press advance, nothing happens. I replaced the 5101 chip... still doing the same thing and the batteries are giving out the proper voltage.

Is there a way to test the switch matrix without diagnostics mode or would anyone know what else I could try to fix Column 3 in the matrix from going bonkers? Any suggestions on the diagnostics problem would be appreciated as well

Thanks!