Grüße aus Iowa in den USA, Ich habe 5 Jahre in Deutschland gelebt und Rothenburg war mein Lieblingsort!

PinballManiac40 offers good advice and the likelihood of a blown fuse based on cascade failures that are quite common to this board. The cascade failures are usually caused by a broken tieback wire (1st failure) which results in a high voltage pulse hitting the drive transistor and causing it to short out (2nd failure); this is turn over heats the coils causing them to melt, which can cause the insulator on the coils magnet wire to breakdown and short (3rd failure) which then blows the fuse (4th failure).

In order to properly diagnose this problem you should perform testing on all parts listed above with power off:
1) You should read a short between the +50V TP (TP6) on the power board and J4-1
2) You should NOT have a short between J4-1 (50V) and J4-7 (GND)
3) With the J4 cable removed, the coils should measure around 10 ohms each between the Pin 1 of the J4 cable and solenoids at pins 2, 4, and 5; and 5 ohms at pin 6.
4) The transistors should have high resistance between J4-7 (GND) and the solenoids connectors on J4 pins 2-6 with the cable removed
5) The blocking diodes should pass a diode test between J4-1 (+50V) and the solenoid connectors on J4 pins 2-6 with the cable removed

If the above tests do not ALL pass, powering on the machine could result in secondary failures as mentioned above.

Yes and no, these lights monitor the boards operating voltages which are +5V and +12V. This board also has a +50V tieback voltage that is required to deal with the high flyback voltages that are created from the coils collapsing fields and this voltage is not monitored.