Hey guys. I am having a tough time tracking down this issue and I would appreciate any help.
Backstory: I picked up a Frank Thomas' Big Hurt that had a litany of problems. I have fixed everything except for one final issue which is a nonworking left slingshot. The original manual came with the game and someone had underlined the left slingshot (Sol. 2) on the solenoid page, so someone else at least knew it was not working.
Repair: F17 was blown below the playfield (the fuse for that solenoid). Q3, the associated IRL530 MOSFET on the solenoid driver board (SDB), was also blown. I checked the solenoid and it was fried too. At this point, I figured the bad solenoid had taken out the fuse and transistor. After replacing the bad solenoid, I removed the SDB to replace the MOSFET and upon doing so, found that whoever replaced this transistor last (I assume the same guy who underlined it in the manual) had bridged the source (S) leg of the transistor to the capacitor directly beside it (C14). That cap (.01uf 50v) also tested bad, but the R64 resistor (2.2k) was still good. After replacing the faulty parts and hooking everything back up, I went into test to activate the solenoid. The moment I did so, F17 blew. The new IRL540 MOSFET and C14 blew again too.
At this point, I thought that the solder short had damaged something else on the SDB. I have a spare SDB that I use for testing so I put that in Big Hurt. All of the same parts (F17, C14, and Q3) blow when the solenoid is activated, so I know the issue is not the original SDB. I traced the wiring to and from the solenoid and I could not find any shorts.
I am looking for some suggestions as to where to check next.
Thanks in advance.