Pop Bumpers stopped working on Earth Wind and Fire

[infinite1977]

Hey guys, was playing my EWF, and had just finally got it working properly, when all of a sudden the pop bumpers have stopped working and the flashing bulbs in the back box have just stopped working. Any ideas?

I have checked all the connectors, and they seem fine. Is there a particular fuse I should be checking a setting?

[Steevsee]

I'd be checking all the fuses on the power board and also under the playfield.  Remove them and test with a multimeter. 

Also check for any signs of corrosion on the fuse clips.

Also check here - http://www.zaccaria-pinball.com/gen1/index.html, under the "Power Supply" section for info on F2 on the power board.

[infinite1977]

Ok checked fuses and indeed it is blowing one of the under playfield fuses and I have no idea why. Any suggestions. Nothing has changed. I have looked for lose wires and can not see any. The only thing that is not connected is the knocker coil, but the machine was working fine like this. If it helps it is the fuse on the left hand side, and it is a 3a fuse

[Steevsee]

So you replaced the fuse and it blew again as soon as you turned on the Game?

Maybe check the pop bumper coils resistance to make sure none have burnt out/shorted.

[Retropin]

Make sure the wires from the knocker coil are not twisted together or touching also...  this will blow your fuse.

You have a short somewhere

[infinite1977]

Thanks Retro, the wires are not twisted together. That was the first thing I checked. I dont even know where to begin looking for the short. I will try testing the coils as steevsee suggested, once I work out how to do it :)

[Steevsee]

Just check each coil with a multimeter on Ohms setting.(one lead on each wire lug on the coil)

Resistance below about 2.5 ohms is bad.

Edit - Check this with the game power turned off.

[Retropin]

Need to verify here that fuse is indeed blowing as start up.

All solenoids fire at once at start up ... its a big rush of current through the fuse so make sure its a good slow blow you have in place.

Im looking at the schematics for devil riders here and it doesnt tell me which is F1 or F2 only that they are both 3A.
What you could do to narrow it down is take off one of the CN17 connectors ( this is split into 3 parts yes?).. 2 larger connectors on RHS and a small one on far left.
Take off far right and see if fuse blows at start up again... if it does then replace and remove middle one etc.
At least then we can narrow it down to a certain row on the cct... might take 2 fuses to get there though... this is where its handy to have 3A, 5a and 10A trip switches... saves running out of fuses.

No one else will read this so its safe for me to tell you that a 5A fast blow is as good as a slow blow 3A .. keep it to yourself though

[infinite1977]

I think I may have found the fault. This pop bumper looks a little suspect. Your thoughts guys

[infinite1977]

My CN17 connector is broken into 3 but it is just one main connector

[Steevsee]

I think I may have found the fault. This pop bumper looks a little suspect. Your thoughts guys

Hard to tell from the pic.  If you have a meter then check the resistance.  This coil should be 7.7 Ohms