Gauntlet Legends/Dark Legacy woes

bones3010

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As my last post indicated, I'm having some issues with my Gauntlet (again)!

Has anyone noticed that these newer machines with supposedly updated/improved hardware seem to screw up more than the 30+ year old machines?

Anyway, lately my machine will randomly reset in the middle of a game. Sometimes it will stutter beforehand (pause for a few seconds, then continue) then eventually restart. Other times when I end a level and the next one loads it will lock up and restart. Sounds almost like a drive issue, but I had another board set awhile back in a different cab that did the random restart thing as well, and while I never officially diagnosed that issue, I DID try a new drive and it did not fix it. So can anyone think of other reasons why this would occur, and a possible fix?
 
As my last post indicated, I'm having some issues with my Gauntlet (again)!

Has anyone noticed that these newer machines with supposedly updated/improved hardware seem to screw up more than the 30+ year old machines?

Anyway, lately my machine will randomly reset in the middle of a game. Sometimes it will stutter beforehand (pause for a few seconds, then continue) then eventually restart. Other times when I end a level and the next one loads it will lock up and restart. Sounds almost like a drive issue, but I had another board set awhile back in a different cab that did the random restart thing as well, and while I never officially diagnosed that issue, I DID try a new drive and it did not fix it. So can anyone think of other reasons why this would occur, and a possible fix?

I had mine for 6 months and didnt have any issues with it but also never played it and when I had people over it went untouched. If you ever sell it your lucky to get 300$ out of it. The game just didnt do it for me or any of my friends
 
I love mine, and my kids dig it too, so I won't be getting rid of it any time soon (unless of course I can't fix it). ...That said, I'll have to hire 3 weight-lifters to get it out of my house: It's about 500lbs and needs to go upstairs out of my basement. I almost killed a friend of mine getting it down the stairs when I lost my grip on it!

Even if I got tired of it, the cabinet is a work of art I think and it would make a nice multi-game if it came down to it.
 
If it isn't your drive then you should try monitoring the voltage because this is exactly what it does when the voltage dips down too low.

For the sake of convenience I monitor mine using the wires going to the joysticks because I've seen that they closely mirror the 5v at the roms.

I'm fighting this same problem right now on my game and I can see that it's voltage related (I can watch the voltage dip down under 4.7v) and the game will stutter and reset. But my situation is a bit more complicated so I won't go into it in this thread.
 
If it isn't your drive then you should try monitoring the voltage because this is exactly what it does when the voltage dips down too low.

For the sake of convenience I monitor mine using the wires going to the joysticks because I've seen that they closely mirror the 5v at the roms.

I'm fighting this same problem right now on my game and I can see that it's voltage related (I can watch the voltage dip down under 4.7v) and the game will stutter and reset. But my situation is a bit more complicated so I won't go into it in this thread.

Hey, I don't want to get my hopes up, but I checked the voltage at the joysticks as you suggested and indeed it was down to about 4.7v. I ramped it up to 5.2 at the switcher (4.9+ at the joys) and I haven't noticed a stutter or reset yet... Keeping my fingers crossed! Thanks for the suggestion, either way!

In a related question, I wonder how a voltage could just get lower like that for no apparent reason. Age?
 
I have the same issue with my Sportstation. except possibly worse. I got 5.40 at the JAMMA edge and I metered ICs and I'm getting like 4.8 at those with the PSU jacked.

it's worth mentioning that the fingers on the JAMMA edge were a little toasty. so I'm thinking that's where the problem lies, with some hella resistance on the fingers.

if anyone has a fix or an idea of what to do for this please share.
 
Poor connections and Drying out caps and heat. Will all contribute to unsteady and unreliable power suppy. Our Older games can handle unstable powersupplies easier than the new games that run faster and need cleaners power supplies to run.
 
I have the same issue with my Sportstation. except possibly worse. I got 5.40 at the JAMMA edge and I metered ICs and I'm getting like 4.8 at those with the PSU jacked.

it's worth mentioning that the fingers on the JAMMA edge were a little toasty. so I'm thinking that's where the problem lies, with some hella resistance on the fingers.

if anyone has a fix or an idea of what to do for this please share.

Pull the Jamma connection off and clean the fingers with an pencil eraser. Resistence = heat. Replacing the jamma connector is a bit extreme but that would solve that problem.
 
Hey, I don't want to get my hopes up, but I checked the voltage at the joysticks as you suggested and indeed it was down to about 4.7v. I ramped it up to 5.2 at the switcher (4.9+ at the joys) and I haven't noticed a stutter or reset yet... Keeping my fingers crossed! Thanks for the suggestion, either way!

In a related question, I wonder how a voltage could just get lower like that for no apparent reason. Age?

If it's at 4.7v then it absolutely is what was causing your issues; that's the threshold at which you get the stuttering and resetting. Believe me, I know all about this because I've been chasing it for a while.

I have a more complicated situation with mine that's been driving me crazy because I'm getting large voltage swings even after replacing the power supply with a new one.

In my case I'm using Bob Roberts JAMMA extension cables as a crude 2 in 1 switcher between GL and NBA JAM and I'm getting this issue with both games so it's not a specific board issue for either game. And it's not a power supply issue either because I've replaced that with a new one. I'm about to try taking the JAMMA extension cables out of the picture to see what impact that has, if any. They certainly add resistance but I'd expect it to be constant resistance, not something that would drop from 5.1 volts to 4.7 over time and different game sessions.

Very frustrating for me, I can tell you.
 
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If it's at 4.7v then it absolutely is what was causing your issues; that's the threshold at which you get the stuttering and resetting. Believe me, I know all about this because I've been chasing it for a while.

I have a more complicated situation with mine that's been driving me crazy because I'm getting large voltage swings even after replacing the power supply with a new one.

In my case I'm using Bob Roberts JAMMA extension cables as a crude 2 in 1 switcher between GL and NBA JAM and I'm getting this issue with both games so it's not a specific board issue for either game. And it's not a power supply issue either because I've replaced that with a new one. I'm about to try taking the JAMMA extension cables out of the picture to see what impact that has, if any. They certainly add resistance but I'd expect it to be constant resistance, not something that would drop from 5.1 volts to 4.7 over time and different game sessions.

Very frustrating for me, I can tell you.

I am wondering How long is the JAMMA extension cable you have? long the wire more resistance.

I wonder if the gage of the wire is too small. Smaller the gage the less current it can handle.

I am thinking either the connector has too much resistance or the wires are too small of a gage.
 
I actually have 2 3' extenders hooked together -- one comes from the power supply, the other goes to the game board. Each game board has an extender going to to it; I just swap the connections to get a theoretically perfect connection on the entire harness.

They're Bob Roberts extension harnesses and he doesn't skimp on wires if you know what I mean. :)

It may be the connectors or a bad wire or somesuch; I'll try swapping them around to see what changes.

I know this adds resistance but I'd expect it to be constant resistance that's added, not jumping all over the place.
 
I actually have 2 3' extenders hooked together -- one comes from the power supply, the other goes to the game board. Each game board has an extender going to to it; I just swap the connections to get a theoretically perfect connection on the entire harness.

They're Bob Roberts extension harnesses and he doesn't skimp on wires if you know what I mean. :)

It may be the connectors or a bad wire or some such; I'll try swapping them around to see what changes.

I know this adds resistance but I'd expect it to be constant resistance that's added, not jumping all over the place.

I wonder what current load your game takes?
The higher the current load the bigger the power cables should be.

OK I found out that bob uses 18 gage wire. (Thanks http://www.hardmvs.com/html/jammaReview.htm )

18 stranded copper cable should give you 6.5227 ohms per 1000 Feet.
Your 6 feet of extension should give you a resistance of 0.0391362 ohms
If your pumping 15 amps (thanks http://www.paradisearcadeshop.com/4-arcade-switching-power-supply.html) down 6 feet of 18 gage wire you should see a drop of 0.5865 volts.
on the 5 volt side so you should end up with 4.4135 volt through 6 feet of 18 gage stranded cable.

If your game become unstable at 4.7 volts either you can up the voltage on the power supply by .5 or .6 volts to over come the resistance in the wire but resistance creates heat.

If we use a bigger gage wire like a 12 gage copper stranded the Voltage drop at 5 volts at 15 amps should the voltage drop is 0.1455 Volts. So If your pumping 5 volts @ 16 amps from the power supply you should get 4.8545.

Less resistance should give you less heat.
Smaller swings of voltages due to the resistance of the wire.

I don't know any arcade game that has a constance current load of 16 amps. Typically the load varies depending on what the arcade PCB is doing.

hmmm there are more than 1 power connector.
There are 4 +5 volts connection 2 +12 volts connection and two -5 volts connections..
18 gage..
3.75 amps per 5 volt connector. Should give you a voltage drop of 0.1466 volts giving you 4.8534 volts at the arcade board. Since the amperage is low on the +12 and -5 voltage drop should be less than .1 volts.

16 gage should give you 0.0919 voltage drop for 6 feet of cable.
14 gage should give you 0.0581 voltage drop for 6 feet of cable.
12 gage should give you 0.0364 voltage drop for 6 feet of cable.


So after all this rambling.

Maybe Just replacing 4 of the +5 volt to a larger stranded gage wire might give you a more stable game.

Just a thought.
 
I think the game (including the monitor and marquee light which aren't powered by the jamma harness) consume about 1.5 amps total.

I really don't know what the issue is but if it were simply a matter of not enough power being able to flow down the +5v 18g wires I'd think I'd have a constant voltage drop off. Instead if seems to go all over the place...

This weekend I'm planning on ending my self-imposed "no game fixing" period and try swapping this back to the original cables and see what happens over the course of a month or so...
 
I think the game (including the monitor and marquee light which aren't powered by the jamma harness) consume about 1.5 amps total.

I really don't know what the issue is but if it were simply a matter of not enough power being able to flow down the +5v 18g wires I'd think I'd have a constant voltage drop off. Instead if seems to go all over the place...

This weekend I'm planning on ending my self-imposed "no game fixing" period and try swapping this back to the original cables and see what happens over the course of a month or so...

Good luck! I'd like to see what you did exactly with your "crude switcher"... I like to cram as many games in to my machines as I can (for example, my Star Wars is switchable for ESB), and right now my Gauntlet is the only "single" game cabinet I have. Not so sure what else would work in a switchable situation for this machine but I'd give it a go! ...what I'd really like to do is simply make this single boardset work with Legends/Legacy, and maybe even NFL Blitz (I think that's the one that used the same boards). ...I did a similar hack with the original Gauntlet I/II, but I realize that's a pretty simple board set from this one. I wish I had a little more of the necessary geek know-how to do this stuff on my own! I'd also create a new hack interface for the old arcadeshop programmable boards.

That said, as an update to my original post, so far so good! The voltage bump seems to be working. I reaaaaally hope it stays, since I hate chasing gremlins. ;-)
 
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