Hello I have a lethal weapon 3 pinball machine which was working great until very recently the DMD display went fuzzy (no clear picture of anything just a load of dots moving around) and the game was noisier than normal, speaker buzzing etc, anyway at this stage the game played as normal with the exception of the DMD displaying garbage.
Things soon went from bad to worse when I tried to diagnose the problem at the power supply board and unfortunately I had an accident with the multimeter probe whilst working at arms length stood on a chair etc I accidently very briefly shorted the +12v test pin at the top of the power supply to the +5v test pin when the multimeter probe dropped through the wire test loop at the top of the PCB.
Now when I power up the game the only signs of life are "I hear the words back in action" and the lights behind the backglass flash alternately as designed I think with the general illumination lamp lit in the playfield.
I have checked voltages on the Power supply with everything plugged in, all the values are reasonably in spec bar the -12v which is reading -15.5v
On the CPU board the +5v LED is constantly lit together with the PIA no flashing of LEDs at all
The power board is original with a few broken fuse holders and soldered in fuses which I planned to repair with new fuse holders (it was on my list of things to do!). I have removed the power board and checked across the fuses with a multimeter and I get a 0 to 1 ohm reading across each fuse so I think they are all OK.
Also there is +5v at the CPU board and DMD Board
I have checked every fuse on this machine I think
I am at a loss were to start with the repair as I don't own another Data east game to swap out boards etc and i am wondering if I have knackered the games eprom or processor chip.
Your help would be greatfully received on this problem before I start replacing things in hope etc
Thanks in advance Dave