I'm having a strange problem with Woz.

The game seems to play fine, but I've had to replace fuse 710 three times in the past 2 days. It doesn't blow immediately so I'm trying to locate the problem. I can play for a quite awhile before the fuse blows.

I found a potential clue, but looking for some advice on how to troubleshoot (or fix) it.

Every coil under fuse 710 works in Coil test, even with the COIN DOOR OPEN. (This is not correct.)

Every other coil NOT in the 710 fuse circuit will only fire in test mode when the coin door is closed (correct operation. )

Does anyone have an idea how or why the coils in the 710 fuse circuit can fire in test with the coin door open?

I'm assuming if this issue is corrected, the fuse may stop from blowing intermittently.

I suspected the small retract coil. I recall it burning during Melt The Wtch awhile back. But it is working. I played a 10+ minute game with the glass off, focusing on hitting the winkie target and bashing the castle doors repeatedly without blowing F710. Doors and target all worked perfectly.

In regular gameplay, it is working fine. The winkie target behaves normally so I assume the switch is working correctly.

I haven't gotten to MTW recently, however the coil wrapper is very wrinkled from getting hot previously when it was held down as required in the final stage of MTW. I had to turn off the game because of the burning smell. But as I play it now (without reaching MTW) the retract coil works during test and gameplay despite the wrinkled wrapper.

Lloyd, are you saying it is normal for all coils under the 710 fuse to fire during coil test without closing the coin door? None of the other coils operate like that.

I thought coil test required that the coin door be shut for any coils to work during coil test without exception.

The only error I receive is monkey magnet sensor D06 switch. But the magnet catches the ball 100% from the right orbit when lit. It misses from the left orbit sometimes. Still need to troubleshoot that, but it seems unrelated. (Where exactly is that left sensor? )

Thanks Lloyd. Yes I know about pulling the door switch to emulate a closed coin door. But I didn't know that some coils will fire in test without pulling the interlock switch or closing the door. I was misinformed reading through other posts.

I was unable to cause the fuse to blow again. I've removed the castle pf several times, so it's possible the issue has been resolved with the last reinstall. I checked the door motor lugs and looks ok.

Right now everything seems fine. I'll have wait if it happens again. I just can't replicate the problem now. Thx.

Well, problem not resolved. Damn fuse burned out again.

It just doesn't happen immediately. Hard to find the source.

I've got 4a slow blow.

The real problem is I can play without it blowing. When it blows, it is not immediately apparent while I am playing. I can play for a couple of hours.

I think maybe the winkie retract coil is suspect because of it heating in the past. Could it be shorting from inside? Is it only during Melt the Witch that it energizes? I will disconnect that little coil and see if the new fuse survives.

The coil blows before getting to MTW.

I can't see that the castle door motor lugs touching anything. The doors work for awhile.

Thx. I'll try this.

So it looks like this target retract (mini) coil is riveted to its base.

I can't find a 23-3013-00 coil replacement on the JJP website. Is there a source for these somewhere?

20200229_194945 (resized).jpg

Is it the same coil that retracts the target on Shadow? it's an almost identical mechanism. Coil SM1-26-600.

Doesn't JJP use BW parts?

Yes I figured it out the expensive way.

JJP was slow to respond, so I bought a B/W matching coil w/ assembly. Athough the coil could be removed from the B/W assembly, the coil on the JJP assembly was permanently attached. I tried a using a dremel to remove it with no luck. Ended up buying the replacement from JJP for $50+.

I was trying to figure out what caused it to overheat. My unproven theory is it occured during a really long Melt The Witch session when I failed to make the penultimate target shot fast enough. I think my coil stayed energized after it pulled down the target during that mode.

They never told me to check the transistor. My coil still worked but might've compromised its resistance after overheating from a prolonged activation.

From my experience, if the transistor fails, my coil would stay energized which wasn't the case. But I will definitely look at it if the fuse blows again.

Also, I broke down and got a Hakko desoldering gun a few years ago which allows you to cleanly remove components in 5 seconds with no heat damage. It was expensive, but ultimately worth it. I don't use it often, but so happy I have it when I need it. (Probably the same cost as sending out a board one time. )

There is a random hurry-up shot requiring that the target must be hit to collect. (Not sure if there are further repercussions if it is never hit.)

Replacing the winkie drop target coil assembly fixed my 710 fuse from blowing. Does the wrapper on your mini coil show signs of having overheated in the past?

That burning smell was my exact experience.

The challenge was trying to figure out the source. The target would still work, but eventually fuse 710 would blow again.

The working theory is that the coil had been compromised. As it heated up, it would short, causing the fuse to blow.