FIRE in the cockpit.....(Atari ARI power PCB problem)

James_in_MD

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FIRE in the cockpit.....(Atari ARI power PCB problem)

I guess I should say "FIRE in the upright" instead. I have been playing a little DK lately and have a few other games on the same switch, including an Asteroids Deluxe and a JAMMA'd Taito that I had just brought down from the garage. So, while Mario was hammerin' away, I start to smell smoke - electrically flavored smoke, if ya know what I mean. I instantly assumed this was coming from the newbie JAMMA cab that I had just powered on for the first time since I got it. I took a look inside it and found no source of the smoke. Hmmm, weird, I thought. I then noticed the AD was not working and shouted, "MAN Down!", and rushed to power it off. I opened up the coin door and a fair amount of smoke started coming out. Damn. I closed the door and then got a shop vac and vacuumed all the smoke out of it - this worked quite well. The vac filter seemd the trap the smoke pretty good. I did a quick look inside the cab and couldn't readily find the trouble. The next day I was at the Crabtowne get together and talked to some folks about the problem. Oryk Zinyo suggested the ARI board. Well, he was right....

2013.02.17.jpg


So, as you can see above that resistor is TOAST. Specifically, it was the 10 Ohm 1/4W resistor at R25. I replaced it with a 1/2 W resisitor that I luckily had on hand.

2013.02.17.jpg


Well, I popped the board back in and it worked! Of course, I did not leave it on that long, cuz I was not sure if I had fixed the real problem or not. I will make some meter readings of the board while it's on and post them here later. Could it be just a bad resisitor or is there something else going on here? Anything in particular I should check?
 
Usually its the edge connector to the pcb.. See if your getting good contact.
Also rebuild that AR!

+1

If you power up that board without a load, it will smoke that resistor. That means that you probably had some vibration on or near the cab that caused the connector to loose connection.
 
Powering the AR boards without the game load fries R29 if I'm not mistaken.

James, bring it to my place when you get the rebuild kit for it and ill help you out.

Definitely check all the connectors, bad connections are a huge cause of the sense circuit frying the power board.
 
Nope, you can power it up minus the pcb.. Shouldn't damage anything.. Just loose connectors and arching electricity will blow the resistor.. And other variables


Powering the AR boards without the game load fries R29 if I'm not mistaken.

James, bring it to my place when you get the rebuild kit for it and ill help you out.

Definitely check all the connectors, bad connections are a huge cause of the sense circuit frying the power board.
 
Nope, you can power it up minus the pcb.. Shouldn't damage anything.. Just loose connectors and arching electricity will blow the resistor.. And other variables

You are correct sir, it's the ARll boards that have the sense circuit.
 
Both the AR and AR2 have "sense". And both will work fine with no PCB connected.

The resistor burns when there is excessive resistance in the normal current path to the PCB, so more and more takes the "alternate" route... through these resistors & the sense lines.

Root cause of the problem likely lies at the edge connector / finger board interface, as local413 suggested.
 
Thanks guys for all the info. I will order a rebuild kit for this board as well as another ARII board I have on hand which will eventually go into another game. Chuck, that would be great to work on them at EOTL. I will check the edge connectors, and I guess the Molex connex that go into the AR as well, right?
 
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