Bally 742 fuse blowing problem

[Rgull77]

I could really use some help here. I have a Bally 742 single coin machine. It had always worked fine. I took the reels out to lube the 3rd reel and shortly afterwards it stopped accepting coins.  I jumped the micro switch and still nothing. Then upon inspection I saw that the center 3amp fuse behind the hopper had blown. I replaced the fuse and it imediately blew again. I could use some hints as to what kinds of things cause this fuse to blow.

Thank you in advance....Randy

[OldReno]

A short to case will blow fuses.
Check this link
http://newlifegames.net/nlg/index.php?topic=17559.0

[Rgull77]

Thanks for the link. That's very good reading there, so now I know that the fuse blows when I put the reels in so I evidently did something when I had the reels out to create a short. I just can't see anything that looks different. If you had a fuse blow when plugging in the reels, where would you look? Could the short still be on the door?
 Randy

[OldReno]

I'd look at the coin relay stack of switches, and your 'c' switches to see if they are touching case.  Use your VOM on ohms to check all your switches.  Clip one lead to case, and then test them all.
Also do the same test on your door.  Check all lights (not the 120V fluorescents) and coils on there. 
And, the #1 door short problem, check behind your coin acceptor to see if there is a quarter shorting across your coin lockout coil.
You're doing this with power down, yes...?

[Rgull77]

Yes, powered down. I've gotten a few 120's in my day....

 So let me see if I understand, you say that if there is a short the meter will read zero ohms? Because I have gotten no meter movement from anything on that door (except the door itself so I know the meter works). The same for the handle release coil, no reading. The lockout coil behind the coin acceptor looks rough but I removed the lockout lever many years ago to prevent the buzzing from it. I also get no reading from that.

The reel mech switches are well away from the case and I see nothing else touching. Do I check the reel mech switches the same way when it's out of the case? Sorry my knowledge is limited. I have a lot of machines but I have never run into a short before. I wish you were my next door neighbor!

Randy

[OldReno]

Well, you are my neighbor.  Yes, check your reel mech on ohms out of the case.  Clip one lead to the metal, and then check all your switches and coils.  You are blowing your fuse because of a short.  Somewhere.  All circuits should be isolated from case.
Check your female beau plugs on the reel mech case side to be sure that one of them hasn't been pushed out to short against the cabinet.  You can do this with your VOM and a paperclip on one lead to check each pin, and clip the other lead onto case.
I love shorts.

[Rgull77]

Well today I checked the reel mech and the Beau plug. I got no readings and everything appeared to be intact. But to my surprise, I got a reading from the coil on the hopper motor. I took a picture of what I found. The hopper doesn't blow the fuse. Is this my problem or is it just another problem?

[OldReno]

That happens all the time.  A little epoxy or superglue should fix that.

[Rgull77]

Hi, When I checked this plug, it registered on on the meter and blew the meter fuse. Perhaps you can tell me what this plug leads too.

Thanks in advance
Randy

[OldReno]

Was machine off when you ohmed it?
Dunno about the plug, trace your wires out and see where they go on the door.  Colors should stay the same....

[Rgull77]

You'd think the shining door lights on would have been my first clue! By the time I realized that it had been plugged in and tried to edit my post, you had already replied. I'll retest when I fix the meter. Thanks....

[Rgull77]

The plug wires leading to the door have no reading. The black wire on the plug that leads to the case reads 0 ohms. It leads to the ballasts for the fluorescent lights in the case. Maybe this is normal.

I rechecked the reel mech and the beau plug in the case, the hopper again. I don't know where else to look. I'm afraid I don't like shorts as much as you..lol

[OldReno]

Yes, I've checked ohms with power on, too.  And have replaced a few fuses on my VOM, good thing they're fused....
I wouldn't worry too much about your fluorescents...  Look at your reel mech plugs on the case side, and see if any of them appear to be pushed back and shorting to case.  You can also ohm them.
Concentrate on the reel mech, since that appears to be the problem area.

[Rgull77]

I agree. I checked the mech plug on the case front and back. Everything is secure and I tested every plug hole as well. I also put an insulator between the plug and the back of the case and between the case and the payout reel boards. This way nothing can touch the back of the case. Fuse still blew. With and without the the hopper in.

I took the hopper out and checked the beau plug from underneath with the reel mech in the machine and verything checked out fine. I don't see anything touching the case visually either.

[Rgull77]

I know shorts aren't very exciting but the Superbowl is over and I'm back to my Bally. Went over the reel mech again, everything seemed fine.

I unplugged the door and put the reel mech back in and the fuse didn't blow. So assuming problem is in the door I checked everything again. I think it may be the lockout coil. It's burned looking and when I try to jump it it does not activate. Will this cause a short? I removed the flapper piece years ago to stop the constant buzzing from it. Maybe it finally just burned itself out. I'll have to replace it although it really isn't needed. Can it be bypassed to see if the fuse blows?

[OldReno]

Sure, you can just cut one of the wires, and then tape it up.  Should not affect machine operation, and it might even make that short go away.
If you cut the orange wire(s) make sure you crimp or solder them together, other wise you may lose some of your 50V.  Just cap off the other non-orange wire so it doesn't touch anything.

[Rgull77]

Done! Machine works perfectly! I can't thank you enough for your help. And what I have learned is invaluable. I am going to donate to this site because I have another machine, a 937 twin lightning, that has been non-op for several years. Maybe I can get it running too.

My 742a in the picture is on the right....

Thanks again
Randy

[Rgull77]

Okay, before I leave this machine (742a) I have two lighting problems I'd like to ask about. The 'insert coin' and the 'coin accepted' lights were jumped together when I acquired this machine many years ago. I am trying to follow the schematic but I don't think the color codes match too well. I believe the wire to the 'coin accepted' light comes from the coin relay switch. Where is this witch?

Secondly, the winner paid lamp is wired to the the lamp above it so they are both always on. There is a wire that lead to nothing, so I clipped it to the 'coin accepted' lamp to see if that was where it belonged, but it lit only during a payout and only while the hopper was engaged. So if this is the 'winner paid' wire, was this normal on older machines? On my other Ballys, the winner paid light stays on until the next handle pull. There isn't a zero stop with eraser head thing on the hopper. You can see the green with black tracer wire in the foreground of the picture.

Perhaps someone with a 742 can help with how this lighting was originally.

Thanks again
Randy

[OldReno]

If my foggy memory is correct, the insert and coin accept lights should go to your coin relay assembly, which is the latching relay on the back lower left of your reel mech.  You can tell by tracing the wire colors, they should stay the same.  The winner paid light should be controlled by a pawl and switch at the back inside of your payout relay board.  Again, check the wire colors.  This should be a single switch with two leaves that stand upright.  Us your ohm-meter if you get lost.  Hope that helps.

[Rgull77]

The 'coin relay' switch was clearly labeled on the mech, so your memory is just fine. The wire to the coin accepted light is an open switch at rest. This functions fine. The 'insert coin' light I would assume is a closed switch at rest and opens when a coin is inserted (this is single coin). Trouble is that the only two closed switches on the relay, will light the insert coin light, but leaves it lit at rest too. Since I have no wire to the 'insert coin' light at all, I don't know where it should be coming from.  Perhaps someone can trace their wire.

As far as the 'winner paid' wire, it leads to the payout relay on the hopper. Perhaps it is just supposed to only light during payout, unless someone with a 742 tells me their machine is different.

[OldReno]

Ok, do you have any unused switch leafs on your coin relay?
Or are there any contacts that don't make to anything?
I think the secret to all this is tracing the wiring out.
See if you can find that latch for the winner paid light behind the payboard.

[Rgull77]

No, no unused switches on the relay. Everything there appears to be original solder. It occurred to me that I can check my 873 and trace it's 'insert coin' wire.

So for the winner paid light, what's a latch? LOL, sorry, I'm not quite up on my lingo.....

[OldReno]

It's a couple of pieces of metal, one side looks kind of like a hook, and the other side latches into it.  It is released once the first coin goes out of the hopper, and it is reset when the payboard reset coil pulls in to reset the hopper.  You probably have to drop down your payboard to see it well.  It should be attached the the reset coil linkage.  Which I had a pic.
And again, make sure all your switches on the coin relay do something, either open or close somewhere.  Look at the color of your coin accepted  light on the door, and see if you can find it on the coin relay switches.

[Rgull77]

That's the problem, there isn't a wire attached to the 'insert coin' light (just the common). So I have been using a jump wire to see which open switch, closes when coin is inserted and opens when the coil resets at the end of the spin to make the light go on then off. The only switch that did that went to the coin lockout solenoid, thats where my short was so I had taped that wire off. Maybe I should just run that wire to the coin accepted light and call it a day! Maybe a newer coin assembly was added later and it didn't originally have a lockout solenoid.....All the wires seem accounted for.

I'm sure getting an education here....

I haven't looked at the hopper yet this morning.

[OldReno]

Well, be careful you measure the voltages before you run the wire.  The coils use 50V, and the lights use 6V.  If that wire is running 6V, then I'd say go for it.
If you have the time and energy you might want to trace and map-out those wires from the coin relay, and see where they all go.  In theory you have one from the coin accepted (missing or taped up) to the coin relay switches, normally open.
You can also check functions on the machine by putting a piece of paper or matchbook in between switches to insulate them and then record how that affects the machine.  How many switches do you have total on the coin relay?