The schematic on IPDB for Cyclopes is pretty good - worst page is the playfield schematic:
I might have a better one - I have to look.
Solenoid Driver Unit, Lamp Driver Unit, MPU-2 and power supply (PSU-1) schematics are the same for all GP uprights
You've received good advice so far, though before you test the regulator you should check the bridge rectifiers on the PS board. If they are bad then the regulator won't get good power to regulate.
As was suggested, the best way to test a regulator is to apply power to it and measure its output with all the other harness connectors removed. Unless you have other specialized test equipment, there's really no way to test it with a resistance or diode test.
Unplug the machine, Remove all the connectors at the power supply and test the bridge rectifiers per the procedure linked to above. Then test the fuses for function and rating. This photo will help you identify the parts:
Game Plan Power Supply Fuses and Rectifiers
If the fuses and rectifiers check out, plug the machine back in, do not hook up the connectors, turn the machine back on and check the voltages with your multimeter at the test points listed below:
Game Plan Power Supply Test Points
There are two things that are troubling to me about your power supply. First, the wires that are directly connected to the power supply at J1. That could be a problem and is certainly a hack and could be causing you a short which smoked the power supply. Second, the burning at the fuse connector for the GI indicates a possible overfusing and a short somewhere in the GI circuit.