NBA Showtime/NFL Blitz Dual Arcade

BGT Masters

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Finally got around to putting the machine together and got to play 4 games before it froze and reloaded. Got to play a few more games then a few days go by and it did it again and now no matter what I do it just says No Signal. Occasionally it will attempt to boot up but to no avail. I tested the power supply. The best I can get by adjusting it is 5.1? +5V, 4.88 -5 V 12.6V and 120V. It was at 5.3 +5V before I adjusted it. What else should I be on the look out for? The only wire I had to wire nut back together was a white wire that ran power to the marquee on top.
 
That Vegas boardset is very power hungry. Unplug the Jamma harness and take a look at where it plugs in to the pcb. Chances are you will see burned marks or damaged fingers where the 5v comes in. This is right beside where the 4 wire molex plug goes to the hard drive. If so, this is your problem.

There are proper ways to fix this, and what follows is not the proper way, but will work just fine. The hack I have used is to find a molex ide hard drive power splitter. Plug one end to the board, one to the hard drive or flash, and the other end cut off the connector and wire to the power supply. This will bypass the jamma connector for power. If you have any old computers, many of them had them. Something like this : https://ebay.us/m/yrhguP

If you really want to give it an operator style hack, skip the splitter and just run an extra +5volt wire wire from the power supply and splice it inline with the red wire going to the hard drive. You can use another wire nut here to give it that special touch and to match you marque wire Set to 5.1 and let it ride
 
Pictures below are courtesy of @vagrant13 who recently sold one of these. These are the pins that are normally damaged and this is how it looks if repaired correctly. If you fix it, you might need to take a look at the Jamma Connector as well. If you hack it, it doesnt matter if the power wires are even in the Jamma Connector


20250505_161241827_iOS.jpg20250505_161249511_iOS.jpg
 
That Vegas boardset is very power hungry. Unplug the Jamma harness and take a look at where it plugs in to the pcb. Chances are you will see burned marks or damaged fingers where the 5v comes in. This is right beside where the 4 wire molex plug goes to the hard drive. If so, this is your problem.

There are proper ways to fix this, and what follows is not the proper way, but will work just fine. The hack I have used is to find a molex ide hard drive power splitter. Plug one end to the board, one to the hard drive or flash, and the other end cut off the connector and wire to the power supply. This will bypass the jamma connector for power. If you have any old computers, many of them had them. Something like this : https://ebay.us/m/yrhguP

If you really want to give it an operator style hack, skip the splitter and just run an extra +5volt wire wire from the power supply and splice it inline with the red wire going to the hard drive. You can use another wire nut here to give it that special touch and to match you marque wire Set to 5.1 and let it ride
it's not power hungry. it just has additional circuitry to turn the +5V into +3.3V for the CPU. if you run the voltage going in over 5.10V and just never clean the JAMMA edge it will eventually burn up. which will result in significant voltage drop between the power supply and SSIO. the long term fix is to channel power supply voltage into the hard drive power on the SSIO as it is directly connected to the JAMMA edge.

also +12V and -5V are unregulated. they're not adjustable. they don't matter. they're never going to be perfectly 12.00 or -5.00V.

that's all I hope this was educational
 
Looks like I'll have my hands full. I am a novice when it comes to any of this stuff and the only thing I even have any knowledge at all is using a multimeter. I unplugged what I believe was the JAMMA harness and didn't see anything but that was before I saw the pictures above to compare it to so I'll take another look. When I watched a how to video it told me to adjust the +5 and -5 to whenever the median range was so its nice to know that was wrong and that only the +5 matters. The game is in a custom cabinet/stand and has already been gone through and has wire nuts, splices act added to it so who knows what's been done to it. I can tell some of the wires have been cut, capped, jumped, etc. It was supposed to work great and I paid ALOT for it so its a bit disheartening its having issues. I'm noticing a trend when buying these things. A lot of them are "fully functional" until i get them home and realize they are projects. I took another look at the connections and they all look fine.
 

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I think you are running into a heat issue. There should be fans pointing at the GPU and CPU. That GPU gets stupid hot real fast without proper cooling.
 
I think you are running into a heat issue. There should be fans pointing at the GPU and CPU. That GPU gets stupid hot real fast without proper cooling.
It happens as soon as its turned on. I thought it was a heat issue and had grabbed a box fan and but doesn't do any good because it goes straight to No Signal seconds after power up.
 
He's right.

You probably cooked the video card. See the original set up with the metal mounting plates and attached fans.

IMG_0512.jpeg
 
He's right.

You probably cooked the video card. See the original set up with the metal mounting plates and attached fans.

View attachment 832167
So what exactly should I look for on that card? Considering I got to play it maybe 4-7 times total (not in a row) before it started happening I am not sure how I burned it up. I even had the cabinet open when I played it. There is a large door that comes off the front of the cabinet where all of the boards are so it shouldn't have overheated. Though I did notice the lack of fans, the only one I saw was in the rear of the cabinet (maybe a 4"-6" one) and not even sure it kicks on. Hopefully its not the norm for the community but almost every cabinet I bought from people has issues when they all were suppose to work fine. Paid almost $4K shipped for this one from a dealer. Was hoping for better results since the first machine I had shipped from them was trash (Centipede). Certainly been in over my head lately but have been plugging away ordering parts.
 
If you are going to collect these things, you are going to have to learn to work on them, and we ALL have dealt with stuff like this. Not sure about your prior experiences with this dealer, but "working" games can often break just moving them across the room. It happens. They should have known better than to send that out without cooling. Definately need to address that and hope no damage has been done.

Yes, thats the jamma harness you unplugged, and the jamma edge connector on the board looks good. Might still be an issue with the connector though.. With the game powered up, take your multimeter and probe that 4 pin connector by the jamma harness while it is still plugged in. You can push the probes in from the backside. Black is ground, red is +5v, yellow is 12v. What does 5v read there?
 
Honestly I'd try to find a way to test the video card if possible. You could get lucky and maybe it's just a simple power issue.

I'm not sure who even repairs these boards.

I have a hard time believing that is a OEM set up with on fans in the board sets.

All I know is when I got mine up and running I was advised not to run the game too long without active cooking. That's why I located the original metal plate to secure the boards and use the original layout for the fan locations.

 
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If you are going to collect these things, you are going to have to learn to work on them, and we ALL have dealt with stuff like this. Not sure about your prior experiences with this dealer, but "working" games can often break just moving them across the room. It happens. They should have known better than to send that out without cooling. Definately need to address that and hope no damage has been done.

Yes, thats the jamma harness you unplugged, and the jamma edge connector on the board looks good. Might still be an issue with the connector though.. With the game powered up, take your multimeter and probe that 4 pin connector by the jamma harness while it is still plugged in. You can push the probes in from the backside. Black is ground, red is +5v, yellow is 12v. What does 5v read there?
You are correct I am going to have to learn to work on these. I just didn't plan on almost every single one I purchased to need work and not function without being worked on. Its a lot to tackle right from the get go. I certainly didn't buy them to collect them I bought them so people could play them. I started the game up and it actually loaded all the way up to where you enter your initials to use your saved character but then it just froze and no signaled me and loaded a few more times but just got worse and worse until it was just NO Signal without loading anything. I tried to get readings but its almost impossible with how the board is mounted, there isn't room to get the leads on the side and the wires are so tight its almost impossible to get the leads to touch anything to get readings.

When I disconnected the harness from the board they read 11.4V, -4.346 and +5.130 (on both +5s). I tried for quite sometime to get my leads to touch the brass connectors and get readings with the harness plugged into the jamma board and finally got a few readings but it took 20 minutes to get them to read anything but that could be because I was flying blind with the leads. Or they weren't getting constant power. I got 5.047 +5 and -4.91 on the -5, I could never get the 12V to pull a reading even though that was the easiest to reach. The one good thing is the entire harness is labeled.
 
Honestly I'd try to find a way to test the video card if possible. You could get lucky and maybe it's just a simple power issue.

I'm not sure who even repairs these boards.

I have a hard time believing that is a OEM set up with on fans in the board sets.

All I know is when I got mine up and running I was advised not to run the game too long without active cooking. That's why I located the original metal plate to secure the boards and use the original layout for the fan locations.


Its obviously a customer set up. I could tell from just looking inside the wiring it had been "customed". I couldn't find a single fan inside the cabinet and even though the game wasn't being used it got extremely warm in there within a minute or two. I do have NBA Hangtime (which has monitor issues and also occasionally restarts) but wouldn't know what or how to swap out boards. A bit paranoid about accidentally frying something else.
 
Honestly I'd try to find a way to test the video card if possible. You could get lucky and maybe it's just a simple power issue.

I'm not sure who even repairs these boards.

I have a hard time believing that is a OEM set up with on fans in the board sets.

All I know is when I got mine up and running I was advised not to run the game too long without active cooking. That's why I located the original metal plate to secure the boards and use the original layout for the fan locations.
Vegas games use an "off the shelf" (sometimes a variant with the passthrough connector left off to save money) Voodoo2. If you have a computer that can run DOS/Win95 and has PCI slots, you can install the Glide SDK and run MOJO.EXE to see if it will boot up or run some demos. If it doesn't work you'll sometimes get a hint of what's wrong from MOJO, like "missing" RAM or an error message about a bad TMU. If it's bad you can either buy a new one ($$$ because you're competing with yuppies trying to build a 90s computer because they saw one in a youtube video) or look around on PC forums like Vogons for repair info.

And yes, you absolutely must have active cooling, the heat these things put out is legendary. I've even seen someone replace the VRM section on a Voodoo3 with an off-the-shelf regulator module, the factory regulator tends to char the board black like a chassis board's power supply section.
 
Finally got around to putting the machine together and got to play 4 games before it froze and reloaded. Got to play a few more games then a few days go by and it did it again and now no matter what I do it just says No Signal. Occasionally it will attempt to boot up but to no avail. I tested the power supply. The best I can get by adjusting it is 5.1? +5V, 4.88 -5 V 12.6V and 120V. It was at 5.3 +5V before I adjusted it. What else should I be on the look out for? The only wire I had to wire nut back together was a white wire that ran power to the marquee on top.
go here and read: https://www.arcaderepair.net/mechas-essential-power-supply-guide-remastered/
 
I repaired one of these. It was a dual mode problem.

Problem 1 was the edge connector, which I had to re-do with copper tape and the @ArcadeJason solder and finger-wipe edge connector repair.

Once I got that fixed, problem 2 popped up, which was the hard drive was bad. I switched over to the Arcade Services SD card, and it was returned to service.

I also had to clean the screen, and adjust the monitor a little, but once I did, it was perfect.
 
Looks like I'll have my hands full. I am a novice when it comes to any of this stuff and the only thing I even have any knowledge at all is using a multimeter. I unplugged what I believe was the JAMMA harness and didn't see anything but that was before I saw the pictures above to compare it to so I'll take another look. When I watched a how to video it told me to adjust the +5 and -5 to whenever the median range was so its nice to know that was wrong and that only the +5 matters. The game is in a custom cabinet/stand and has already been gone through and has wire nuts, splices act added to it so who knows what's been done to it. I can tell some of the wires have been cut, capped, jumped, etc. It was supposed to work great and I paid ALOT for it so its a bit disheartening its having issues. I'm noticing a trend when buying these things. A lot of them are "fully functional" until i get them home and realize they are projects. I took another look at the connections and they all look fine.
What is the little 7 segment display doing on the CPU board when the game is powered up? In your photo is the one with the "0" on it. Is it just displaying a number or is there a bar scrolling up and down?
 
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