Arcade Collecting > Restorations & repair
1981 Ms. Pac-Man restoration
Finalheaven:
--- Quote from: Level42 on May 30, 2010, 04:19:09 am ---Mistakes is how we learn :) Trust me, I've been there and still make plenty mistakes !
The Pac Man Joystick is IMHO one of the best arcade controls ever. It's also sturdy and relatively easy to get into a great like-new shape.
Definitely worth it.
--- End quote ---
Yeah, agreed. I was worried more about the stuck down situation. It seems my error in judgment is absolute though. I had the spare parts in one plastic bag, and trash in another plastic bag. I ended up throwing both out. Yup, that's right. I mistakenly threw away an original Ms. Pac-man joystick. :banghead: <---- x1,000,000^42
I'll have to look for another original somewhere.
In the meantime, in between long bouts of kicking myself in the butt, I've been checking the wiring. The Brown/white striped wire is the lead for the down arrow. I unplugged that wire and she still went down. I disconnected the control panel molex and she still went down. I followed the brown/white wire all the way back to the long black pin connector on the PCB. I disconnected the pin connector and looked for anything that might indicate a short anywhere near that brown wire and found nothing. I also disconnected the molex leading to the coin door, just in case, and she still went down. I'm guessing that the short must be occurring on the PCB itself? I followed the pin the brown wire connects to on the PCB, to see if any of the nodes on the PCB relating to the down direction were located near a sloppy solder of some sort. I found nothing. So, I'm stumped. I doubled checked the wiring schematic in case I was missing something, but it's pretty straight-forward. My board does have the 12/7/81 revision by V. Caporusso that adds the credit multiplier PC and the fluorescent light.
Back to the drawing board.
Finalheaven:
So, I used the multimeter to measure the pins on the 74LS chip responsible for joystick movements.
I found the pin layout (if that's the right term) for the 74LS367 chip responsible for up-down-left-right. I also found this great site (http://lawnmowerman.rotheblog.com/logicprobe.html) that basically lays out how to measure it.
I used my schematic and found that pins 14 to 13 are responsible for Down on the 74LS chip at location 8E. I also learned pins 10 and 9 are responsible for Up. Basically, I measured the voltage between pins 14 and 13 and found they were always at 4 volts (I had my multimeter set to AC10V). Pins 10 and 9, 6 and 7, and 4 and 5 were 0. I then measured pins 10 and 9 while the up switch was depressed and it read 4 volts. When turned off, it went back to 0. So pins 14 to 13 are always on. What does that mean? Bad 74LS chip? I also learned R45 and C20 are the resistor and capacitor responsible for down, respectively (220 ohm, .1 microfarad). I have no clue if the Res. and Cap. are contributing to the problem.
I think there is light at the end of this tunnel.
Finalheaven:
Picture of the cabinet and screen (while it's working):
http://www.dragonhooker.com/images/pacman/cabinet_back.JPG
http://www.dragonhooker.com/images/pacman/cabinet_front.JPG
http://www.dragonhooker.com/images/pacman/cabinet_screen.JPG
saleem:
are you going to keep the art or are you going to give it a stencil overhaul?
it certainly looks like a sturdy cab.
:)
Finalheaven:
--- Quote from: saleem on June 01, 2010, 11:00:24 am ---are you going to keep the art or are you going to give it a stencil overhaul?
it certainly looks like a sturdy cab.
:)
--- End quote ---
Despite the sun bleaching, I think I'll keep the original artwork. It may be faded, but that's part of its authenticity.
I have two steps now. I'm going to replace the 74LS367 chip (install a socket and then the chip in slot 8E) and I'm going to rewire the pin connector with one of these: http://www.twobits.com/Pacmend/.
Anyone have any suggestions for which IC 16 pin socket to use for 8E? There seems to be a lot of choices. Overwhelmingly so.
Navigation
[0] Message Index
[#] Next page
[*] Previous page
Go to full version