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):
PsbCn1ConnectorSchematic (resized).png

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):
BridgeSchematic (resized).png

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.

Thanks for the tip. I wondered about that.

The reading across the two wires is 31 VAC (spec is 25 VAC). The brand new rectifier I installed yesterday is outputting 29 VDC. This is the same output as the old one, which makes me think it must not be the issue either. Still, 5 VDC below spec sounds like a lot to me. (BTW, I'm getting this reading by placing the DMM leads on the + and - terminals of the rectifier.)

I'll take @Inkochnito's advise and start looking at the PSB.

I tested the old rectifier under load, but the new one with no load. I will recheck the new one under load tonight and report back.

Thanks for your suggestion.

I'm connecting the wires to the rectifier posts with quick connectors. They fit perfectly. Solder instead?

The ground from this and another rectifier go to a separate connector on the PSB board (CN2) :
CN1-CN2Schematic (resized).jpg

Last night I took voltage readings from the questionable rectifier (by setting DMM to read DC voltage and placing the leads on the + and - terminals), both with and without the CN2 connector plugged into the PSB board. Without CN2 connected, I get 29 VDC - same as before. With CN2 connected to the PSB, I get a whopping 48.3 VDC. I also took readings with and without CN1 plugged into the board ("with load"?), but it didn't change my readings.

So, is this user error? Did CN2 need to be connected to the board all along?

By the way, here's what CN2 looks like on the back of the board. The char marks look troubling to me:
IMG_1639 (resized).JPG

So, here's a dumb question...how do I check this? I have sharp point leads. Can I get a reading if I stick them in the female connector leading to the DMD? When I do this I only get 0.5 volts.