Firepower
Williams, 1980It seems like the answer should be "no". But I'm trying to figure out why a Firepower blows the solenoid fuse immediately on turning the machine on. It's not something on the power board, I've swapped boards with the same result. And all the solenoids test with 5-6 ohms resistance, so no shorts there. Seems like a br could be the issue, but they test ok for continuity / directionality.
Quoted from chad:Possible bridge in backbox counld be faulty.
So they can be faulty even when they test as ok?
Quoted from chad:Fuse value is correct?
Fuses are all correct.
Quoted from EvanDickson:Fuses are all correct.
I would change the sol bridge and see.
Quoted from EvanDickson:So they can be faulty even when they test as ok?
Yes, sometime things can fail while under load or when heat enters the picture.
In your case, be sure to check for shorts. Maybe something was wired up incorrectly?
Original design on firepower the bridge was never fused. If youre 2.5 amp sloblo fuse is blowing on the power supply the issue is not your ridge rectufier but a short somewhere or bad coil, knocker coil possibly.
It would be prudent to add a fuse on the 2 panel mounted rectifiers in back per pinwiki suggestion.
unplug the solenoid outputs before you change a bridge , see if the fuse still blows , if it does , you have your answer.
Pull the bridge and power up. Does the fuse still blow? If yes, then its not the bridge. If no, put the bridge back in and unplug the connector that it leads to. Work down the line. until it starts blowing again and you'll find your culprit.
Might be a good time to invest in a circuit breaker so you aren't eating up fuses.
Another thing to check is your fuse holder. The contacts need to be perfectly
clean and no corrosion. If there is enough resistance between the fuse
and its contacts a lot of heat will be generated causing the fuse to fail.
In my experience high current bridges usually fail open, not shorted.
Let us know what you find.
Steve
Wanna join the discussion? Please sign in to reply to this topic.
Great to see you're enjoying Pinside! Did you know Pinside is able to run without any 3rd-party banners or ads, thanks to the support from our visitors? Please consider a donation to Pinside and get anext to your username to show for it! Or better yet, subscribe to Pinside+!
This page was printed from https://pinside.com/pinball/forum/topic/can-a-bridge-rectifier-test-as-ok-but-actually-be-not-ok and we tried optimising it for printing. Some page elements may have been deliberately hidden.
Scan the QR code on the left to jump to the URL this document was printed from.
Charlottetown, PE
New Kensington, PA