Bally Pool Sharks (Bally, 1990) F4 Fuse Trouble

Cpoov

Pinball Nudger
Joined
Nov 6, 2018
Messages
5
Reaction score
0
Points
2
Favorite Pinball Machine
Pool Sharks, Attack from Mars
Hey there! I am new to Pinball Nirvana and looking for some help. I've scoured and scoured through countless threads so I am trying to get some active help. I have a Bally Pool Sharks, when I got it it had some problems, the right slingshot was stuck, countless blown fuses, etc. Fast forward to today. Currently I am having issues with F4 which controls both drop targets, talking sharky, and both slingshots. This blows as soon as the machine is turned on. The fuse gets about 76VAC. I've replaced the Q14 transistor as i saw on other threads that it was a possible cause but with no luck.

Any ideas would be greatly appreciated!!

Thanks for helping out a new member!
 
As well, there was a burnt coil which has been replaced, and no stuck switches. And it is still blowing
 
If you have a dmm test br1 on the power supply for shorts. A bad bridge would take out that fuse right away. We are talking about f4 on the power supply correct?
 
Last edited:
I'm talking about the F4 Aux power driver unit board.
 
Unsolder the single wire that goes to each of the coils in question then test if f4 blows. If it doesn’t resolder each wire one at a time and test each time until the problem coil is found.
 
On two of the coils (one drop target and one slingshot) there is only single wires going to each prong of the coil, to properly test should i unsolder one or the other or both?
 
On coils with both single wires, only one has to be unsoldered .
 
Unsoldered all of the single wires and it is still blowing on power up.
 
The f4 fuse also controls the common return line for the 50v coils on the a side of the a/c relay. Keeping the original wires unsoldered, unsolder these violet with color tracer wires from these coils. Left and right drop target resets, diverter , and knocker. Test for fuse blow on power up. Inspect and check coils for shorts. Resolder wires until fuse blows to find bad coil.
 
Forum activity
Help Users
You can interact with the ChatGPT Bot in any Chat Room and there is a dedicated room. The command is /ai followed by a space and then your ? or inquiry.
ie: /ai What is a EM Pinball Machine?
  • No one is chatting at the moment.
      Chat Bot Mibs Chat Bot Mibs: Beers is our newest member. Welcome!
      Back
      Top