Millipede locking up...suggestions?

MonsterBash

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Here's what I've done so far....
Tried a different transformer
New big blue
Tried a different arii...I also caped the arii and change the resisters
I think its a board issue

So if I increase the voltage on the board to 5.15 it locks up durning attract mode or when playing almost always on the third board. If I decrease the voltage to exactly 5.0 (measured at the board and the 6205) it plays longer...but will eventually lock up. I've replaced the 6502 (cpu..it might be a 6205..posting from my phone) and the 2 pokeys

There are no RAM or ROM errors in the self test. I've cleaned the edged connectors and spent about an hour going over the pcb looking for smoked parts and touching up some solder

I thought it might be a ROM issue but its weird that as I decrease the voltage down to 4.90 the stability increases. My ROM burner was supposed to be here friday but never showed up

Is it worth a shot to recap the pcb?



Any other suggestions?

Thanks!
 
After you've run it for a while do any of the components appear to be overheated?

And have you tested for the correct voltages after the game locks up?

Darren Harris
Staten Island, New York.
 
Doesn't appear to be an overhearing thing as it'll run all day in attract mode. I did test the voltage after a lockup and its the same as before the lockup.

I've also played a game with a dmm on the board test point and notice no voltage drop when the game locks up

I did consider try a little fan just to see if the lockups go away. I'll probably try that tomorrow when I get home
 
Last edited:
Here's what I've done so far....
Tried a different transformer
New big blue
Tried a different arii...I also caped the arii and change the resisters
I think its a board issue

So if I increase the voltage on the board to 5.15 it locks up durning attract mode or when playing almost always on the third board. If I decrease the voltage to exactly 5.0 (measured at the board and the 6205) it plays longer...but will eventually lock up. I've replaced the 6502 (cpu..it might be a 6205..posting from my phone) and the 2 pokeys

There are no RAM or ROM errors in the self test. I've cleaned the edged connectors and spent about an hour going over the pcb looking for smoked parts and touching up some solder

I thought it might be a ROM issue but its weird that as I decrease the voltage down to 4.90 the stability increases. My ROM burner was supposed to be here friday but never showed up

Is it worth a shot to recap the pcb?



Any other suggestions?

Thanks!

Recap won't hurt. I recap all my PCB's now if I have to work on them.

It could still be a ROM error and pass the tests. The best thing to do is actually verify the ROMS in your burner (when it shows up).

If you have a logic probe, when the game locks up, on the 6502 check:

Pin 40 (Reset): Is it High, Low, Pulsing? What was it before the lockup?

Pins 9 - 25, and pins 26 - 33 to see if you have any activity.

If you're not getting any activity on 9 - 33 it means the CPU isn't doing anything. At that point you'll want to make sure you have a good clock.

Looking at the Schematics, I would look at pin 12 of 6C and the Transistor at Q1. If you're saying that adjusting the voltage affects it, it could be a flaky transistor.
 
Thanks..I'll try those suggestions when I get home. I do have a probe

I've been leaning towards a corrupted ROM image since this started happening because after the lockup...if you cycle the power you get ROM garbage on the screen. You need to turn the machine off and wait about a minute to get it to boot

Thanks again
 
So during attract mode pin 40 is high.

After the lockup (while its still locked up) pin 40 is low.

All other pins have activity during attract mode and 'lockup' except pin 6..it has no activity during either.

About all I had time to do as I'm heading out the door.

Recap won't hurt. I recap all my PCB's now if I have to work on them.

It could still be a ROM error and pass the tests. The best thing to do is actually verify the ROMS in your burner (when it shows up).

If you have a logic probe, when the game locks up, on the 6502 check:

Pin 40 (Reset): Is it High, Low, Pulsing? What was it before the lockup?

Pins 9 - 25, and pins 26 - 33 to see if you have any activity.

If you're not getting any activity on 9 - 33 it means the CPU isn't doing anything. At that point you'll want to make sure you have a good clock.

Looking at the Schematics, I would look at pin 12 of 6C and the Transistor at Q1. If you're saying that adjusting the voltage affects it, it could be a flaky transistor.
 
Thanks..I'll try those suggestions when I get home. I do have a probe

I've been leaning towards a corrupted ROM image since this started happening because after the lockup...if you cycle the power you get ROM garbage on the screen. You need to turn the machine off and wait about a minute to get it to boot

Thanks again

This sounds more like a heat related problem then any thing. I would start feeling the chips to see if anything is super hot. Wait for it to lock up and then check the chips.
 
This sounds more like a heat related problem then any thing. I would start feeling the chips to see if anything is super hot. Wait for it to lock up and then check the chips.

I mentioned the over-heating issue, but he responded that the game will run all day in attract mode.

But the symptoms still point to over-heating somewhere. I assume he re-seated all the chips and checked their legs, but what I was thinking is that the activity level and therefore power draw of different components would have to change when the game went from attract mode to game play, so the ability to run in attract mode is a different kind of stress than the stress you get once you hit the start button.

As for a bad chip could something be creating a short between two legs? (Perhaps freeze spray would help in this situation).

Darren Harris
Staten Island, New York.
 
So of course I was able to play the game for over a half hour without a lock up. I did however feel around for hot chips and all seemed about the same. There was one IC at the top of the board that was a little hot to the touch. I'll probably have a little more time tomorrow to mess with it, the game has been on for about 5 hours now

I mentioned the over-heating issue, but he responded that the game will run all day in attract mode.

But the symptoms still point to over-heating somewhere. I assume he re-seated all the chips and checked their legs, but what I was thinking is that the activity level and therefore power draw of different components would have to change when the game went from attract mode to game play, so the ability to run in attract mode is a different kind of stress than the stress you get once you hit the start button.

As for a bad chip could something be creating a short between two legs? (Perhaps freeze spray would help in this situation).

Darren Harris
Staten Island, New York.
 
So of course I was able to play the game for over a half hour without a lock up. I did however feel around for hot chips and all seemed about the same. There was one IC at the top of the board that was a little hot to the touch. I'll probably have a little more time tomorrow to mess with it, the game has been on for about 5 hours now

If you have a can of Freeze Spray, you can hit that chip with it when it locks up and see if it fixes it.
 
I swear Atarti's HATE me...

I left the game on while we headed out to the fireworks last night..

I came back to no picture and the game locked up (solid P1 and P2 lights).

Power it down...and back up. Now it plays blinds..no neck glow at all

Damn monitor looked to be in REAL nice shape..not an ounce of burn.

Didn't get a chance to look at the B+ as it was midnight

Ordering a bunch of parts including caps for the PCB..a cap kit for the monitor and gonna cap the Arii (the capped one I have is from my SW)



If you have a can of Freeze Spray, you can hit that chip with it when it locks up and see if it fixes it.
 
I checked the fuses at the brick and at the monitor...voltages are exactly the same.

I did get my eprom burner..all the eproms tested fine. I did erase them and reburn them.

I capped the arii-04 board last night also (the capped arii-02 was from my star wars) and changed the BR in the power brick.

Will probably get more time at it this weekend



A fuse? Check the voltages now.

Darren Harris
Staten Island, New York.
 
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