27-Apr-2016 (Wed)
Wherein I would like to trade alcohol for the repair of obsolete electronics.

Our Pac-Man machine is hurting. Sometimes it does this, and sometimes it does this:

I imagine it just needs some caps replaced and some cracked solders fixed. Are you a person who is competent to fix such things? Are you willing to do so in exchange for drink tickets and admission to shows? If so, I think we have a lovely future together.

Also -- and this is probably a much harder project -- you know the Snarkatron, the big, slow-moving, low-resolution LED sign hanging from the DJ booth that lists our upcoming events, and the DJs at Bootie and whatnot? This thing:

Well, it's hurting too. It's getting kind of hard to read. At first you might think that it's suffering from some burned-out LEDs, but I'm pretty sure that's not the case: what's actually going on is that the letters are corrupted: like, sometimes the letters are not only missing pixels but actually upside down -- but only in some rows. You might see a right-side-up and an upside-down "T" on the screen at the same time.

The sign actually belongs to John, even though it's been hanging here for seven years now, but every time I mention it to him he just mutters something about shift registers and yells "Just throw the god damned thing away already!"

So, do any of you want to take a crack at fixing it?

It's not a particularly useful device, but it's unique and cool looking. And yes, I know I could replace it with a cheap TV, but you know what TVs are not? unique or cool looking.

14 Responses:

  1. Jim Sweeney says:


  2. Jake Nelson says:

    Let me be the first to uselessly and unhelpfully state that if I were in geographical range to inexpensively drop by, I would very happily take that deal, but I am not. Everyone else can skip that post now, I called dibs.

  3. Karl says:

    I am fully aware that this is not helpful, but if I were in SF I'd do it.

    Also, a possible use for the LED sign: https://goo.gl/photos/53zU4dNTqsUF2hpm7 (be sure to play the video)

  4. jwise says:

    I had been noticing at Death Guild on Monday night that the sign seemed unusually sad. I do have an electronics workbench at home with at least the capability to go touch up solder joints and such things, which I imagine is probably the bulk of what's up with the sign. If it'll fit in an average sized car, I imagine I could take it home one Monday night, take a crack at it over the course of the week, and send it back up the next Monday. (The usual lack of guarantees apply as to whether or not it'll actually work any better after I'm through with it.)

    • jwz says:

      That would be awesome, thanks! The thing is like 6' wide and stupidly heavy, so that depends on your car. It is a predictably enormous pain in the ass to take it down and re-hang it. To make it light up, you need to talk to its serial port.

  5. Brickr says:

    Sure, I saw a similar problem with the NTSC frontend on a Q*Bert machine. It's usually not caps, it's one of the voltage regulators, but I've got spare ICs.

    The LED sign is a big question mark, but I've fixed more complicated things. I've also not fixed more complicated things. Anyway, I have to take it apart before I can say anything intelligent.

  6. Bill Paul says:

    John actually asked me about fixing the snarkatron a couple of months back. The problem with repairing it is that you need some technical info like the schematics or a service manual to get started. It could just be a matter of some bad solder joints, but if it's any more complex than that, the more details you have about the hardware the better. I have an EE degree, but I'm not psychic. ("Oh, that transistor needs to be replaced? Gee, it's too small to have the full part number printed on it, guess I'll have to refer to the schema-[annoyed grunt]!")

    I searched online as best I could based on the meager info I had about the make/model but came up empty. John said he had a bunch of info and would send it to me, but so far has not. (He said this to me at the DNA one night after Hubba though, so I might have been speaking to drunk John instead of sober John.)

    We never discussed the logistical issues like getting the thing down and such. (I live walking distance from the DNA, but I wouldn't want to carry it home on my back.) By the time we go to that point I think he'd convinced himself to just replace it with a monitor.

    • jwz says:

      Well, we're not gonna replace it with a monitor ever. So the options on the table are A) leave it alone until it is completely illegible then junk it, or B) there really isn't a B so far.

      • Bill Paul says:

        Well, let me see if I can some more info out of John. I have a copy of the program he wrote to talk to it, but that's about it. (It identifies it as a Trans-Lux Datawall, but other than telling me it's obsolete, the googles do nothing.)

  7. Dusk says:

    Does the Pac-Man machine consistently "dance" to the music, or is that just coincidental?

    If so: can you get it to do this by thumping the side of the cabinet, or does it only do it during shows?

    • jwz says:

      It started being music-reactive recently, yes. Punching it works too. It's actually kind of cool looking, but it does not improve the gameplay.

      The FFFFFFFFFF thing is intermittent.

  8. Chris Yeh says:

    Punching it is a classic case of solder breaks. You just need to pull out all the boards and reflow all of the solder joints. A low wattage pen on everything should do it.

  9. I'm going to be in SF in a few weeks for my job all summer, and I muck around with arcade machines. It looks like you might have a H-K short developing in Pac-Man's CRT. A cap kit would not be a bad idea either. If the PCB hasn't been cleaned up and modified to take DC, that would be a good thing to do as well for longevity.

  10. Conor says:

    Your Pac-Man CRT is on the way out. You could put in a new flat screen, but that would suck.

    The FFFF stuff is quite possibly down to bad contacts on the graphics ROMs. You can pop out any socketed ICs and clean their pins with an ink eraser or similar gentle abrasive and reseat them carefully but firmly. If you don't get good haptics putting them back in, the sockets may need replaced.