Missile Command - Runs then Dies

ArcadeTechGW

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Donor 5 years: 2012, 2022-2025
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Hi,

I'm re-working a Missile Command that last was in operation in 1992 (I know, good luck).

The good stuff - everything is there, except the back door.

The unit fires up, and will play games for around 15 minutes, then....

The display inverts, there is a high pitched sound, the coin interlock drops out, and the machine locks up.

I'm suspecting that the rectifier board is experiencing a heat-up issue.

I'm wondering if anyone else has seen this, and if they have any suggestions.
 
You probably want to rebuilt the AR2 first. Then check for any burning on the edge connector. May need to replace the wiring harness connector housing also.
 
Checking power is always a good idea. Looks like after a chip heats up it dies. If you have a can of freeze mist or a compressor with an air nozzle you can try cooling individual parts then resetting the game to isolate which one it is. The eight 4116s and the 74LS42s are notorious for dying on these boards.

Bill
 
AR2 Readings

Well, it was interesting firing up the unit.

Here are the PS readings - they are all over the map.

-22 Volt rail reading -16.69 vdc
+22 Volt rail reading 15.67 vdc
12 Volt rail reading 12.13 vdc
-5 Volt rail reading -5.14 vdc
10.3 Volt Rail reading 9.8 and falling

36 VAC rail reading 35 (furthest TP from rectifier)

36 VAC rail reading 12 voltes (closest TP to recitifier heat sink).

So, at a minimum, it looks like the rectifiers that support the +/- 22 volt rails need to be replaced. I'm at a loss as to why the 2 36 volt AC rails are different.

Anyone have any ideas?
 
Missile Command doesn't use either + or - 22, so you might as well leave alone.

The 36VAC is centre tapped, so could be that you are reading the centre rail (which should be 50% of the 36).

I'd be tempted to focus on the 10.3VDC. IIRC this comes of the rectifier board on the power brick. Only 3 parts on that: 1 x big blue, 2 x rectifier diodes.
 
I had that problem, and it was the main PCB. Sent it out to be fixed, and am good to go now. Thanx Bill.
 
Latest Update on Missile Command

Well, I went through all the connectors between the main PCB, the ARII, and the Power Brick, and burnished them. Then I started the point to point resistance checks.

I still had a problem with one of the AC rails having low volts, so I pulled the power brick, and started testing point to point there, when I found a problem. When I went from F3 to the source, I got infinite resistance. I checked the fuse, it was good, so I burnished the socket, and now the machine works.

Here's the funny part - my 36 VAC rails are reading around 12.6 volts AC. I went from the rail connection to the ground on the same side of ARII - there aren't any instructions on how to do this otherwise.

However, Missile Command is now up and running. I ran 4 games on it, back to back to back to back, with no failures. I'm leaving it on overnight as a proof test, then it's off to the hardware store to get a lamp for the head (and a new starter), and to Menards to cut a new piece of particle board for the back panel, and I'm back in business.

Woo hoo? Any thoughts on the 12.6 VAC on the 36 volt rail?
 
Here's the funny part - my 36 VAC rails are reading around 12.6 volts AC.

The Missile Command transformer outputs 25vct not 36vct so your AC is spot on. It might be labeled as 36vct on the Audio/Reg but it is closer to 25vct.

Brian
 
Missile Command Redux

Noted. The game actually had the whole drawing kit - I wish I had a scanner - the drawings here have the pin numbers "rasterized" to the point where you can't really read them.

The ARII board is stenciled 36VAC. However, the power in from the transformer is 25 VAC.

Now all I need to do is make a new back door, replace the power cord, and replace the head lighting, and probably take the coin mechs apart and clean them up too, since they are a little off, and I'll be in good shape.

Another game up in the arcade - HooWa! 3 to go, plus two really weird electronic gumball machines, each of which is missing critical parts.
 
Bad fuse holder - suggested sources?

While I was working at the Arcade, I heard Missile Command whining. It's the same thing - half of the input voltage is dropping out.

I have a bad fuse holder. Bad fuse holder! Bad! Go to the corner!

Does anyone have a good source for replacements? Hopefully, it's someplace with a rebuild kit for the trackball - it needs new bearings and new roller pins.
 
Found Bob Roberts

Well, I hit the web, and found what I needed with Bob Roberts. I have emailed my order. Hopefully, this kills off this one, so I can work on the other ones.
 
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