Bally 891 blowing 110 volt fuse [resolved]

[essmeier]

Edit:  This one's solved, but I never did find a definitive cause.   I tweaked a number of things, and I guess one of those things fixed the problem.

I'm more or less done with my rewiring nightmare on my 891-20 Super Continental, and I've finally got it working in both coin and replay mode - mostly.
Three times this week, the game has blown the 110 volt fuse.   Sometimes it plays for a while before blowing, but the last time it happened on the first spin after I powered it up.  The fuse blew while the reels were still spinning.

I've often blown 6 volt or 50 volt fuses, but never the big one.

It would seem to me that tracking down a 110 volt short should be a relatively easy matter, but I can't find anything obvious.

I've mostly been doing work in the hopper area, so that would seem to be the most likely area to look, but I can't find anything.|

Suggestion as to where to look?  I'd assume that I'm looking for a 50 wire (white) shorted to ground somewhere, but...

[DavidLee]

Sounds like one side or the 110 has gradually made a short.
Check the payout relay on back of the hopper as 110 travels through the relay to power the motor.
Usually the white blue wire are involved in motor operation, check the associated contacts and solder connections.
When the hopper is in shorted mode. Check individual wires with a meter for grounding.

[wolftalk]

assuming it's only the 110V fuse blowing now, check everywhere wire 50 connects.  When it connects to relay switches, manually operate the relay and make sure the switch blades aren't touching places they shouldn't.


intermittents are fun.  It may be worth getting a 5A pushbutton circuit breaker and soldering a blown fuse either directly to it or use some wire if space won't allow.  e.g. [size=78%]https://pinside.com/pinball/forum/topic/making-and-using-a-fuse-breaker[/size]


fuse blowing while reels are spinning helps a little because a bunch of stuff is disconnected by open reel mech switches.  However, the hopper mixer relay is powered and connecting some payout safety stuff in the 110V circuit. 


if fuse only blows during reel spin or payout that's another hint the issue could be in the safety circuits.


take a look at the capacitor on the delay relay coil to see if there's any obvious bloat.  Doesn't mean it's good if it looks ok, but if an end is bulging out or it's leaking, you know it's bad.

[essmeier]

Thanks.  It seemed to me that the most likely cause is a 50 (or 52) wire shorting to ground somewhere.  I just wanted somebody to confirm that.

 Apparently, the relay with the capacitor is the delay relay.  I did not know that.

With the exception of the relays in the feature unit, no relay in this machine is labeled.  I've identified most of them, but only on an as-needed basis.  I haven't yet had any business with that particular relay, so I haven't taken the time to see which one it is.   When I'm done with this machine, I'll eventually label all of them for future reference.

I did some extensive checking on the hopper the other day and noticed that the terminals from the payout counter reset coil are really close to the some contacts on the hopper mixer relay that carry a 50/52 wire pair.  Those terminals are supposed to be protected by small pieces of plastic tubing, but they've shrunk with time and no longer do that.

I fixed that, and then tested briefly, but only in credit play mode.  I played until I got a winner, which took 14 plays.  In that time, the fuse held up.

That might have been the cause of the problem.  Hard to say, as I've found no smoking gun here.  But I've recently replaced the male and female beau plugs on the hopper and extensively rewired a bunch of other stuff in the hopper vicinity, so I assume that my problem is likely to be in that neighborhood and not, say, up in the feature unit, where I haven't done any recent work.

At that point, also occurred to me that the tabs on the 17 switches that control coin/credit play might be coming in contact with the metal wall of the cabinet and that I should probably put a piece of tubing on the contact for each switch.

I've now rewired that and I'll install the switches again and see if the fuse holds up.

More when that happens.

[wolftalk]

the solenoid coils - the ones with the plungers going into them - can usually spin a bit in either direction since the rectangular base where the wires connect to the lugs may not be held down firmly onto the frame by the coil stop.  You gotta make sure the lugs/wires can't touch anything adjacent or to the metal unit frame if that happens.


don't assume someone installed the coil in the correct orientation on the coil stop.  If you need to remount the coil 90 degrees from the way it was installed to prevent a lug from touching something, it's a good bet someone put it on wrong or it's the wrong coil.



the replay/coin selection switch bracket should be holding the switch stacks pretty far away from the metal walls of the cabinet, but if you don't have any insulators on the wires/blade lugs, that can be a problem.  You don't need to insulate every connection - bally sometimed alternated between the plastic sleeve and an uncovered wire/lug so the bare lugs could only touch a sleeved lug if someone yanked the wire harness.


on my 929 tho, they sleeved all the lug connections on stuff around the handle area of the game.


if you use shrink tubing as the sleeve, choose a diameter that fits snugly over the tab/solder joint without needing to shrink it around the wire.  Makes it easier to poke a meter probe in there if needed.

[DavidLee]

Hopefully you’ve eliminated the problem. Both ares a likely potential areas to short out.
Specially if it started gradually and then just became a solid short.
As I posted previously.

[essmeier]

The payout counter reset coil is mounted in the only orientation that will work, due to other hardware being in the way if you rotate it.  But as I said, I think I've cleared the conflicts out of the way.

I just played for about 15 minutes in replay mode, and the game is working more or less correctly.

I just switched it to coin mode, and the hopper mixer relay seems to be engaged, and the hopper is churning continuously.

Gotta look at that next.  Likely a minor problem as it hasn't been happening previously.  On the plus side, the fuse doesn't seem to be blowing anymore.

[essmeier]

Took the hopper out and did a minor tweak on the switches on the mixer relay.  I don't know if the two wires that meet there (50/52) were inadvertently touching or not, but I made sure they're not going to do that.

I put the hopper back in and powered it up.

Working correctly and paying out both coins and credits now, when appropriate.

The 110 volt fuse is no longer blowing.

Still have a couple of other minor problems with this machine, but I'll start new threads for those, as they're unrelated to this one.

Thanks to all for the help.