Hello folks! First post, loving this forum so far. A few may know me from AtariAge, making my first adventure into pinball just now.
I recently picked up a mostly working Police Force for what I think was a great price. The main issues were a cracked but functional middle ramp, which is typical, a somewhat wonky display and a lack of general illumination. Following some info from here and other sites, I have made some general repairs (cleaning sticky drop targets, fixing a broken kickout, etc) and lots of cleaning. Since it was playing very well, I decided it was time to do some serious damage.
I began to dig in to the GI lighting issue. Both the backbox and playfield were completely out. I checked all the fuses for continuity, looked at all the connectors and pins for damage, and looked at both relays for obvious damage; everything looked ok on visual inspection. Then I took my multimeter and started poking around on the power supply. I thought I would check for voltage first and "checked" between a ground pad and what seemed to be an 18V pad. Everything went dead, the backbox knocker went off and I thought I heard a slight crackle from the area of the transformer or the box the power switch is connected to. After coming to grips with the horror of the situation, I found three fuses had blown on the power board, 4, 5 and (I think) 3.
I checked to see what the correct fuses were and replaced them. Now, not only is the GI out, much of the controlled lighting and all the displays are out as well.
I would be interested on any perspectives on what I have done to my poor machine. I found what looks like a great modern replacement for the board at pinballpcb.com (link below), but I would like to have a go at fixing this one as I obviously need the experience. I know you really can't test a capacitor in circuit, but two of the three big ones have continuity through them, which I don't think is good news.
Incidentally, in researching what fuses were needed, I realized that I had been missing the fuse for the GI (on the side of the backbox) all along. I replaced it and watched it blow a few times, so it looks like there is a direct short I will have to track down.
Any helpful or derogatory comments would be great, but if they are derogatory, at least make 'em funny!
Note: I can't post the link to replacement board as a noob, but it is easy to find at pinballpcb.com