Wavy Pac-Man Cocktail Monitor

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Howdy.

I can get more details about my specific monitor the next time I open up my machine, but I wanted to get a post out to see if anyone had any ideas first.

I just picked up a Pac-Man cocktail table. It's entirely original (to the best of my and the previous owner's knowledge) and in beautiful shape with one exception:

There's a very slight "wave" in the monitor. It's clear, sharp, and bright, but there's a constant, light wavering effect. The previous owner mentioned something about changing the fuse holder, but I know very little about the electronics of these cabinets. Any ideas on how to fix this issue?

Any help would be awesome. Thanks guys!
 
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Wavy

I have one doing a similar thing on my to be repaired for others list. It has a replacement vision pro in it. I am hoping to get to it in the next week. If you have not figured it out by then, I will let you know what I come up with. I am sure someone already in the know will chime in first.
 
Well, a faulty fuse holder is a common cause of this problem. Another common failure is a dirty edge connector on the game PCB. Open the thing up and have a look. The game harness should go straight into the game board. If there is a small intermediate board that goes between the harness and the board, unplug it, remove it, and plug the harness straight into the game board. That filter board isn't needed, and can be a source of bad connections.

-Ian
 
Well, a faulty fuse holder is a common cause of this problem. Another common failure is a dirty edge connector on the game PCB. Open the thing up and have a look. The game harness should go straight into the game board. If there is a small intermediate board that goes between the harness and the board, unplug it, remove it, and plug the harness straight into the game board. That filter board isn't needed, and can be a source of bad connections.

-Ian

There's no filter board - the harness plugs straight into the main PCB.

When I look inside, there are 7 fuses on the floor of the cab, split into two different holders (one with 3 fuses, one with 4). Are these the holders that I need to replace? If so, any recommendations for what to replace them with?

I found a folded sheet in the bottom of the cab that looks like instructions for a cap kit. On that sheet, it describes steps on how to modify specific capacitors to prevent "horizontal curl", and I'm wondering if that fix might help. When I get home, I'll post the exact details of that instruction sheet. I'm not sure I'm comfortable re-capping the monitor (I've never done it before), but there's a first time for everything...
 
fuse

the best place to start would be to replace all the fuse holders, and fuses. they are known source of this prob.
they need replacing after 30 yrs
they are avail at radio shak
be sure to make a good solder connection when replacing
you may need to remove like 1/4" of wire from ea end to make sure you get good clean non corroded wire to attach to new fuse holder end tabs
 
I'll start with replacing the fuse holders. Again, are there any specific recommendations on brand/type/model of fuse holder to use? Remember, I'm pretty new at messing with the electronics inside these cabs.

Secondly - and this question might be stupid, but I'll ask it anyway: If this cab is entirely original, does it reduce the value/collectibility to replace a part like this with something that's not original?

Lastly, here's the last paragraph on the cap kit instructions I found. The cap kit, according to the info I found at the top of the sheet, is from Peach State Distributing, and it's labeled "Kit #101 Installation Instructions". Here's the last parapraph:

"IMPORTANT! Be sure to install the negative lead of the C302 into the hole with the black dot shown on the top side of the chassis. The (+) sign on the bottom side of the C302 is marked incorrectly. The last step is to install a sync modification which prevents a horizontal curl. This step is optional. On the monitor board, replace C303 with the 10 uF @ 50V capacitor with the positive lead connected to the collector of X305. Then replace C501 with the capacitor taken from space C303."

It's the "horizontal curl" part that interests me. :)
 
1) I bought a few from Mouser to have on hand. I don't have a number @ the moment but can look it up if you want.

2) absolutely not. If it's broken the value goes down.

3) it's a minor change if your monitor has a bit of curl on the top. You can always try it and if it doesn't suit you, change it back.
 
Here's an analogy: if your '57 Chevy's fuel filter was original, would you keep it on there, or replace it? Of course you're replace it. Think of the fuse holder like that - it's a part that has worn out and requires replacing. Without it, it's just a big wooden box with electronic parts inside.
 
3) it's a minor change if your monitor has a bit of curl on the top. You can always try it and if it doesn't suit you, change it back.

The fact that that was found in the cabinet may also mean it's already been done, along with a cap kit. Just speculating, could tell for sure with some pictures. And of course how long ago would then also be another question.

Start with the fuse holders, common problem, common to have replaced.
 
1) I bought a few from Mouser to have on hand. I don't have a number @ the moment but can look it up if you want.

2) absolutely not. If it's broken the value goes down.

3) it's a minor change if your monitor has a bit of curl on the top. You can always try it and if it doesn't suit you, change it back.

Ah, that makes more sense. Now that I know what they mean by "horizontal curl", I know that it has nothing to do with my monitor's problem.

if you can look up the number on those fuse holders, I'd really appreciate it. Thanks to all for all the help. I'll replace the fuse holders and post an update with the results.
 
if you can look up the number on those fuse holders, I'd really appreciate it.

It's a fuse holder. While there are probably part numbers for them somewhere, it's still just a fuse holder. You can get them anywhere. :D

That being said, Bob Roberts is an excellent source of parts for coin-op games. The "wavy Pac" problem is so common, he even sells a kit of parts to replace the fuse holder and the edge connector at once :
Fuse block with 22/44 Molex connector with split pins $8.50
He also sells just the four position fuse block for $4. You can also get one at Radio Shack.

Basically, in almost all cases, this is the fuse holder, the edge connector, or both. Try cleaning the edge connector on the PCB with alcohol on a paper towel. Really do your best to scrub it clean. Check for burn marks. Start with the fuse holder, it's a really easy thing to replace. Replacing an edge connector takes a bit of skill with a Molex crimper, and takes a rather long time.

The problem with the fuse holders that Bally used is that they just lose their spring tension after a while. The metal fatigues and corrodes. Many times you'll find one where an "ear" of the fuse holder has broken clean off, or does break off when you take out the fuse.

Don't worry about the G07 "curl mod", that's a different problem, usually it only shows up on newer Jamma games anyway. The picture will be stable, just warped a bit at the top.

-Ian
 
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