Ok, admitting it. Still a noob here when it comes to these things. I am trying to find out what the best way is to test for a short on a game. I have a Stern (Rippley Believe it or Not), that had some weird issues, which thought to be on the driver board, but it turns out they might not be. Longer story, under a separate thread actually. To cut things short, while testing for the other error, I somehow managed to create a short that keeps on blowing my 50V fuse (f21) on the driver board. I know it must be beyond the J9 connector, because it does not blow, when I disconnect the J9.
It's coils and flipper on the J9. So I assume, something beyond the J9 is creating the short, right? Or could a short be created by a blown FET that sits before the J9? Even if it is blown, the current could not find it's way back, right? So the fuse only blows once the J9 is connected and the current can flow through the coils and back causing the fuse to blow?
If there is a short beyond the J9 (not on the board), how would the fuse even blow? Wouldn't the FET have to open first for the current to flow?
I guess I sort of just answered my own question, but here is the funny thing. The FETs all test fine with the diode test. So they seem to be good. Any pointers appreciated. If it is the board, I'll send it out to somebody who knows what they are doing, but I want to make sure that I am not wasting the time and money and the error is somewhere else.