Greetings, tech wizards. Newbie here. I have a half dead MSF - only general playfield and half the backglass lights come on. I will also occasionally hear a solenoid "kick" and what sounds like an engine slowly turning over. I'm aware of the DMD issues common with this game, but this problem seems larger than that. (By the way, this game was working 100% a month ago.)
After checking all the fuses, I suspected a power issue. I checked the voltage coming into the PSB and found that it was under spec on two of the (cn1) connector pins. The schematic calls for 32VDC, but I'm only reading 28.85VDC. Here's the schematic (it's a little fuzzy, but I'm referring to the 2nd and 3rd lines):
Continuing upstream, I found that the voltage coming from the bridge rectifier (br2) was only 29VDC. Again, this under the spec of 34VDC. Here's the schematic (see green box):
Even further upstream, the transformer feeding the bridge rectifier comes from two wires. One measures 44VAC the other 15.6VAC. The schematics show that this should be 25VAC (see blue box in previous schematic). I think this means that my transformer is producing enough juice, but I'm not 100% sure.
So, yesterday I replaced the (br2) bridge rectifier with a new 35A 400V bridge (http://a.co/dOSXEnC). Sadly, no change. Same 29VDC voltage output as before. Frankenstein is still dead. So, my questions are...
1) Am I getting enough AC voltage to my bridge rectifier? If so, what would cause it to output -3VDC under spec?
and, more generally...
2) Am I completely off base with my diagnosis? Maybe 29VDC is actually enough juice and this bridge rectifier thing is a red herring.
Thanks in advance for your help. It's very much appreciated.