Bally Alpha 2 CPU resets after loading alpha OS

[Shammuu]

Hey guys I have a Bally Alpha 2 that will reset during load. I’ve tried to replace the Power supply and that was a no go. Any help would be awesome! 


****Video****
https://youtu.be/LN7imFi8XWk

[idesign]

Looks like it's having trouble with the OS.  Have you tried re-installing it?

[rickhunter]

I have 5 MPU's that do something similar.  I have not been able to find a fix for it.  Some of them get to the game screen and reboot.  I've changed everything on the MPU with known working parts and still have the issue.  I'm thinking the MPU mainboard itself might have some issues with caps, I just have no way of testing each of the caps.

[Stayouttadabunker]

The 1st time the MPU reset is when it was trying to load the video drivers, the 2nd time it reset was during OS loading....seems to rest even quicker.

Something could be overheating more and more causing it to reset sooner?

I'd be pulling out that MPU unit and checking the thermal paste under the heatsinks and checking MPU fans for clean operation.

[idesign]

The 1st time the MPU reset is when it was trying to load the video drivers, the 2nd time it reset was during OS loading....seems to rest even quicker.

No, that part is normal, it’s not resetting in between where the screen blacks out.


I was wondering if the backplane is causing this.

[Harvs]

I have 5 MPU's that do something similar.  I have not been able to find a fix for it.  Some of them get to the game screen and reboot.  I've changed everything on the MPU with known working parts and still have the issue.  I'm thinking the MPU mainboard itself might have some issues with caps, I just have no way of testing each of the caps.

Same here. I tried everything also and ended up replacing the CPUs. (All were 2.0's, never had this happen on 2.1's btw)

[rickhunter]

2 of the 5 are 2.1's, so for me at least, it happens in either one.

[Shammuu]

Looks like it's having trouble with the OS.  Have you tried re-installing it?

Yes we had this issue before and left it alone with no HDD then installed a fresh burned copy of fire link and it had the same issue.

[Shammuu]

The 1st time the MPU reset is when it was trying to load the video drivers, the 2nd time it reset was during OS loading....seems to rest even quicker.

No, that part is normal, it’s not resetting in between where the screen blacks out.


I was wondering if the backplane is causing this.

I also have some that reset/freeze with the bonus games and we have notice the Mosfets are showing some discoloration so we were thinking the mosfets are underrated. Have you encountered this?

[Ayub]

I have same issues I close to 15 to 17 CPU they all are doing the same thing keep rebooting I have changed Graphics card, SSD, MPU power supply. I try everything thing. Still no luck look like to me it has to do with a MPU logic board.

[idesign]

Sounds like a overheating issue then.  Are all the fans working in the CPU, especially on the heat sink on top of the processor chip? Maybe redo the thermal paste on the heat sink for a test.  Otherwise it's probably some other IC on the board that is weak and just fails after a minute or 2 under load. 

[rickhunter]

I re-did thermal paste on everything and still does it.  My guess is like you say, some component is borderline and fails after stress.

[Shammuu]

Sounds like a overheating issue then.  Are all the fans working in the CPU, especially on the heat sink on top of the processor chip? Maybe redo the thermal paste on the heat sink for a test.  Otherwise it's probably some other IC on the board that is weak and just fails after a minute or 2 under load.

I think it’s a problem with the mosfet chips cause if you look at some boards the mosfets are getting so hot it’s burning the board. Plus if you look at the new 2.1 boards they got rid of the mosfet chips I’ll link photos.

[Stayouttadabunker]

I'd remove it, run some voltage thru it and get some readings with an oscilloscope to see if it stays within specs.

...but that's me....


You can check with a multimeter easily enuff.....no guessing....probably shorting out?


They should have a number on them and you can google the specifications it should fall in.

Can you take a good close up photo of them?

https://www.utm.edu/staff/leeb/mostest.htm

[Shammuu]

This is the Bally Alpha2.1 CPU and you can see that the mosfets have been removed.https://drive.google.com/file/d/15wvIKCXy81794Px598oEm73heyLcMGAM/view?usp=drivesdk


This is the alpha 2 CPU that you can clearly see the mosfets have over heated and burned the board and the chips are bloated.
https://drive.google.com/file/d/1E0kRPdcDZvztZcG9KG7PPUVtN-_Ernj_/view?usp=drivesdk


And here is the board that doesn’t have overheated mosfets what it should look like
https://drive.google.com/file/d/1CUaNBPj2otWrt_XoQ0vD809lOqWSlCfr/view?usp=drivesdk


My thought is that if there’s a mosfet we can replace those with that run higher voltage or just replace those ones and put heat sinks on them to dissipate heat more.

[Stayouttadabunker]

They look shot....replacing them may not fix your problem as somewhere down the line something other IC component also may have become corrupted.

Also, it's possible you don't even need them to run a machine in a home environment?
I  would look into if they're needed or not.

At this point, that MPU is pretty much on it's way out?
I'd remove those severely damaged ones at the very least and see what happens.

[Shammuu]

They look shot.

Also, it's possible you don't even need them to run a machine in a home environment?
I  would look into if they're needed or not.

What are you trying to say?

[Stayouttadabunker]

Some components on slot machines are only needed for casinos for record-keeping and tracking purposes.


However, your problem is it's possible these heat damaged mosfets (among possible other damage) are making your machine shut down.


I don't know what they're being used for?

Your best bet is to replace the entire mpu and rule it out.

[Shammuu]

Some components on slot machines are only needed for casinos for record-keeping and tracking purposes.


However, your problem is it's possible these heat damaged mosfets (among possible other damage) are making your machine shut down.


I don't know what they're being used for?

Your best bet is to replace the entire mpu and rule it out.

As much as I’d like to do that these MPU aren’t cheap. Mosfets are tho. If i can just replace the mosfets and put a heat sink on them maybe the issue will go away. In theory...

[Stayouttadabunker]

As much as I’d like to do that these MPU aren’t cheap. Mosfets are tho. If i can just replace the mosfets and put a heat sink on them maybe the issue will go away. In theory...

Yeah...but you don't know what else is blown outta specs...

Put in new Mosfets and they blow right up again is what I'm thinking...
I'm thinking there's a voltage regulator somewhere in the line behind them that's allowing too much juice to go into those mosfets....remember, mosfets are only like railroad track switchers.