Bally SS Xenon (Bally, 1980) - On board solenoids not firing

[sweetdiggity]

My parents have a XENON that we recently got up and running with the help of some local pinball gurus. The game worked well for a few months but now none of the solenoids on the board are firing, during the test on the kicker in the box #2 fires.... Here is some history

with help from friends
1) repaired a2 power board
2) repaired a3 solenoid drive board
3) powered up with no luck
4) added new Altek MPU board a4
5) powered up but kept blowing f4 fuse during play
6) replaced transistors and heat displacement update on power board

worked well for a few months

7) Jan 8th blew f4 fuse again.
8) replaced f4 after looking for loose connections, wires etc ( none found)
9) worked for about 8 more games then during a game it all froze after the ball went up the ramp into the side saucer
10) checked for loose wires, free moving solenoids or any visible issues, none found
11) replaced Playfield fuse which had blown, f4 was fine
12) game boots but solenoid test still only fires #2, kicker in the box and none of the other solenoids fire
13) voltages all appear to test ok on the power board and solenoid driver board

looking for the next steps.......and trying to repair on my own without having to bring in my friends again....
have read about similar issues but also a bit of a newbie. Tempted to buy a new solenoid driver board but not sure that would even solve the issue

thanks in advance
Pineappleracer

@pinballdaveh

 

[sweetdiggity]

checked test point 5 again and slow-blow playfield fuse and holder. 43 V and ok but Still no further progress yet

 

[Isaac Sauvage]

Unfortunately it doesn't seem like DaveH is around these days.

I'd recommend asking this one at Pinside or r/pinball.