I neglected to take a couple of before pictures to show the nasty grime covering these three G07 chassis, but we’ve all seen similar parts. Any arcade pcb’s that have been sitting around in a warehouse for 20 plus years are bound to be covered with crud. Makes it hard to see what you’re working on when trying to do repairs and sometimes a standard cleaning just doesn’t do the trick. So into the dishwasher they go!

I put three chassis’ into the dishwasher on normal heat settings with no detergent of any kind. I did give them a quick spray of simple green to loosen things up a bit. As you can see the parts came out very clean. Not 100% showroom floor clean, but so much better now that I can actually read the print on the pcb.

After the dishwasher process I used some compressed air to blow out the obvious pockets of water and then I let the three chassis sit on a wire shelf in the laundry room to dry. The heat from the dryer got them nice and dry in no time, but I still let them sit for several days. Next step is to do some rebuilding and see if I can get them working. Only issue I had was the “warm electronics” smell left in the dishwasher after the pcbs had been in there. Not a huge deal, but I had to run it again to get the smell out.

The cage itself prevented effective troubleshooting, it was just in the way. What to do? Build an equally complex testing harness and power supply, of course. After many days of painstaking labor to develop and build a dedicated test station for Cube Quest, the tech was finally ready to get down to business.

After only a short time, the technician was able to get the board working, as you can see. One interesting bit about this game is that it was designed to work and play even if (or should I say when) the laser disc player failed. What you see here is game play minus the laser disk effects. Still pretty cool. The next step is to restore the sound and then connect the laser disc player to see if it will all work together. Want more info about this particular game? Check out the post over at rotheblog, happy gaming!

The next step was to bring my pcb over to Bill K for testing on his Cinematronics setup (Vectorbeam pcbs are practically identical), but I never made it that far. I decided to re-install the monitor and the new ribbon cable from Mark H. before pulling the pcb. Game fired up with no shakes. Here’s the new ribbon cable installed.

Solution: New ribbon cable eliminated the shakes from the vector display. Pretty easy solution this time around, now I just need to turn down the brightness!

The scope leads were then connected to the sound test points on the AR II, with the same result, except the square wave was amplified (larger). This ruled out the AR II pcb as the cause of the problem because the oscillations were the same. The noise was originating from somewhere else. We had to take a closer look at the schematics which I didn’t have on hand, but could easily find at the arcade archive. The schematics show that the audio section on the pcb can be traced back to leg 37 on the pokey, a likely culprit as they are known to fail. Quick history of the name…”The pokey is an I/O chip used by Atari in many of the classic era games, its name comes from POtentiometer and KEYboard, as it was commonly used to sample (ADC) potentiometers (such as game paddles) and scan matrices of switches (such as a computer keyboard).” – Wikipedia. We powered down and swapped out the pokey with a known good chip, but there was no change. Isolating pin 37 on the pokey, responsible for audio output, also gave us the same wave display result on the o-scope. This ruled out the pokey.

Since it appeared that the pokey was good, the likely problem was now with the audio portion on the pcb. That was all we could do at this point because I didn’t have any of the audio amp chips on hand to replace or piggy-back onto the existing chips. Bill took the board home to change out the chips and capacitors from the audio section. I took this opportunity to lay the game down and add some gliders (levelers with nylon). This would allow me to move the game around a lot easier without damaging my floor like the metal levelers do.

Picked up the repaired Warlords pcb from Bill along with a spare pcb Bill had on hand, just in case. Installed the original pcb into the game and fired it up. Same problem with absolutely no change. Installed the spare pcb and got the same noise issue, but at least I was able to verify it was working and also potentially rule out the pcb as the noise problem. At this point I was a little irritated and because I use tokens to run my game room, the coin door on the cab was open to allow me to easily add credits. I closed the door a little rough and got a fluctuation in the sound, interesting. Opened the door and noticed the sound fluctuated as I moved it around. Jiggled the coin door wires and got the same changes. So now it appears that the connection to the coin door is the issue. With so many wires and connectors to check, this is going to be a pain. Bill stopped by later that night to poke around at the coin door. He moved wires, jiggled coin mechs, pulled on coin shutes and then moved the slam switch. Huge change occurred. Bill pulled the leaf apart on the switch and the sound vanished, bingo!

Solution: Slam switch on coin door was closing/sticking with door movement causing leaf switch contact and the horrid sound. A simple piece of blue tape between the switch contacts keeps them from closing and the sound is gone. I guess it pays to check ALL the simple solutions before running the repair gauntlet, but at least I learned a few things.