Introduction and need a little help; Defender arcade coin mech not responding.

olePigeon

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Introduction and need a little help; Defender arcade coin mech not responding.

Howdy,

First post, first arcade, first time trying fix anything arcade related. :) I originally posted on the Build Your Own Arcade forum, but they don't have a very active user base. Donated a few bucks so I could post on here, seems this forum is really hopping.

I've gathered from the few posts at the other forum that I did a pretty good job getting my Defender arcade. I'm really happy with it. I've since fixed a battery problem, I noticed some corrosion on the battery holder. I took the board out and gave it a good scrub with some baking soda and isopropyl alcohol. Now my arcade keeps high scores and settings, which is important because the coin mechanism doesn't appear to be working. I've set it to Free Play, so that helps.

Anyway, I was hoping someone could point me in the right direction on how to troubleshoot and maybe get the coin mech working. I'm a complete newb when it comes to arcades, and I'm hesitant to start poking around short of just making sure the cables are all plugged in.

I did notice that there are light bulbs behind each coin slot, and those are not lit up. So if I had to guess, maybe the coin mech isn't getting power?

Below are some pictures of my arcade. Everything's orignal. Unfortunately the control overlay was melted by cigarettes, and the joystick is a little loose. The cabinet, however, looks like it was fresh from the factory. I'm really digging it:
 

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Some more pictures of the boards:

(Edit: Dang it, I seem to have deleted the other board pictures. I'll post them when I get home.)
 

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Did you try replacing the little light bulbs in the coin slots? They are almost always burned out. I'd bet they come on if you replaced them.

Have you tried manually flicking the little wire at the bottom of each coin mechanism (carefully) to simulate a quarter going past it?

What happens when you put a quarter in? Does it go all the way through?
 
Derp. Didn't think to change the bulbs. I'll take them out and see what kind.

As for the coins, they go in just fine and right into the cash box with a satisfying clank. :) Unfortunately it doesn't register that a coin was inserted.

Likewise with flicking the wire, doesn't register anything.

I was looking at some of the amazing restoration threads. Maybe if I take a lot of pictures and label stuff so I know where everything goes, I should just dismantle all the electronics and wires and give them a good scrub.
 
Howdy,

First post, first arcade, first time trying fix anything arcade related. :) I originally posted on the Build Your Own Arcade forum, but they don't have a very active user base. Donated a few bucks so I could post on here, seems this forum is really hopping.

I've gathered from the few posts at the other forum that I did a pretty good job getting my Defender arcade. I'm really happy with it. I've since fixed a battery problem, I noticed some corrosion on the battery holder. I took the board out and gave it a good scrub with some baking soda and isopropyl alcohol. Now my arcade keeps high scores and settings, which is important because the coin mechanism doesn't appear to be working. I've set it to Free Play, so that helps.

Anyway, I was hoping someone could point me in the right direction on how to troubleshoot and maybe get the coin mech working. I'm a complete newb when it comes to arcades, and I'm hesitant to start poking around short of just making sure the cables are all plugged in.

I did notice that there are light bulbs behind each coin slot, and those are not lit up. So if I had to guess, maybe the coin mech isn't getting power?

Below are some pictures of my arcade. Everything's orignal. Unfortunately the control overlay was melted by cigarettes, and the joystick is a little loose. The cabinet, however, looks like it was fresh from the factory. I'm really digging it:


Do you know if it's the original power supply or if it's been upgraded to a switcher?

If you are not sure, post a pic of the bottom inside of the cabinet.

If you have a multi-meter you can start by testing the switches. They can go bad, but the odds of both of them going bad are pretty slim. However, it's an easy test and a good way to rule them out.

I would check all your ground wires going to the coin door. If it's been upgraded to a Switching Power Supply, then chances are it needs an extra ground wire run to the coin door.

If it's the original power supply and all your ground wires appear to be good, then it's probably a PCB problem (starting with the IO Widget) and will require more involved diagnostics.

Do the service switches work? (3 buttons, red and black on the coin door)
 
I could be completely off base here; but does defender register coin when set to freeplay?
 
You could put it in diagostic mode and check the switch test to see of any of the switches on the coin door are registering.

If nothing is registering, try resetting the coin door connector on the ROM card (with the power off). And repeat the switch test.

If you still aren't seeing any coin door switches you may need to get the PIA chip on the ROM card or the buffer chips between the PIA and the coin door replaced. A logic probe would help to see if the signals are getting between the connector and the PIA inputs.

ken
 
Awesome suggestions! Thanks! I'll take some pictures of the power supply and bottom of the cabinet and give the diagnostic mode a whirl.

Best I can tell, it doesn't register coins even in Free Play.

There is a toggle power switch in the front under the lip of the cabinet, beneath the coin box. The fellow I bought it from said he didn't know if it was original, or if it was installed later so you didn't have to reach to the back of the arcade. I wonder if this could have something to do with it if it wasn't done correctly.

In any event, I'll post back here this evening after I get home.
 
Awesome suggestions! Thanks! I'll take some pictures of the power supply and bottom of the cabinet and give the diagnostic mode a whirl.

Best I can tell, it doesn't register coins even in Free Play.

There is a toggle power switch in the front under the lip of the cabinet, beneath the coin box. The fellow I bought it from said he didn't know if it was original, or if it was installed later so you didn't have to reach to the back of the arcade. I wonder if this could have something to do with it if it wasn't done correctly.

In any event, I'll post back here this evening after I get home.

The power switch is original.
 
In regards to the service switches, actually, no, they don't all work. The left push button doesn't work, I have to short it with a key to make the number for the settings go down. The other two buttons work fine.
 
Best I can tell, it doesn't register coins even in Free Play.

ok so you tried it both ways? just checking, I've been retarded enough to think something was wrong in one or two boards until I snapped that free play was on; and was expecting coins to register. DOH!
 
I got it working again! I was taking a picture of the underside of the coin mechanism when I noticed that the little wire wasn't in the groove on the side of the metal housing of the coin mechanism for 2 of the 3 coin slots.

I then noticed that the copper strip that makes the contact wasn't slotted correctly in the round, plastic covering for the coiled wire spring. I took out my screwdriver gently nudged it until it was in the little slot, put the wire back into the groove, and now I have three fully operational coin slots. :)

Works when I flick the wire and put quarters in. I'm going to stop by the bank and pick up a couple dollar coins and give the center one a try.

Next step is to fix the left switch that I have to short, and replace the 3 bulbs so it lights up. :D

Will also need to get a replacement overlay. Maybe some new buttons for the control panel, and I'll need to take apart the joystick and see if I can't get that working better.

Thanks for the tips! I'll post some pictures of the power supply anyway, maybe someone might spot some preventative maintenance I can do.
 
Here's the power supply. It's a bit dusty in there, I've only cleaned the other boards.
 

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Forgot to mention that I ran the diagnostic, and everything checks out. No bad ROMs or anything. Looking good so far. :)
 
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