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PGM single game PCB assembly and troubleshooting

rewrite said:
Fixing this brought back my sound, and now I can get mid-way through Stage 1 before it crashes.
Everything is facing the right direction. And I've scoured both boards for unwanted bridges.
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Did you burn the program rom into a different EPROM, in case the one you're using is not 100% working?
 
Fluffy said:
Did you burn the program rom into a different EPROM, in case the one you're using is not 100% working?
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Not yet. But I'm betting that's where the issue is!

I set Jumper 2 and played through 4 stages of Arrange with zero issues. Removed Jumper 2 and back into the normal romset and it crashes in stage 1 still.

That's sound logic given the issue at hand, yes?
 
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As an update after the old burner had crapped out I had sent the files for Espgaluda off to buyicnow "Well the other two are made so this will be cheaper" was the original intent but it basically confirms the other eprom contents are suspect as the cart works perfectly fine. I have some other projects that have jumped ahead in wanting to get done sooner so I'll pop back in a few months when I've had time to revisit them.
 
Then it's not the file itself.

And it seems less likely it's P1 since I've tried two and they all read out the same against my file.
 
I'm in the same boat, P1 has tested correctly and I even replaced it.

I've just finished up something I've been working on, I'll pull out the PGM and check the resistor array
 
So on my resistor array, if I measure pin 1 and any other pin I get 10k ohms. If I measure any other 2 pins together I get 20 ohms. Is someone able to confirm if this is the correct circuit or do I need to order a different resistor array?

I'm getting pretty much a perfect 10k resistance on all the pins, 1-2% out on a couple of others so well within spec as long as the circuit is as required.

It looks correct

@rewrite are you able to meter yours out?
 
Good point, but they are different games so I wasn't sure if it could still be the issue.

I also have no jumpers set in case that's a potential issue.
 
xodaraP said:
So on my resistor array, if I measure pin 1 and any other pin I get 10k ohms. If I measure any other 2 pins together I get 20 ohms. Is someone able to confirm if this is the correct circuit or do I need to order a different resistor array?
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That is expected behaviour.

There were a few reports of a game crashing until SRAM is cleared. That is the switch next to the test button. (I am not sure if you have to switch it while the motherboard is off, while switching it on, or while it is on, etc.)
 
I've done that several times both with the switch and in the service menu, across 2 motherboards. It's cleared lol

The fact it boots to the copyright screen and then crashes means it's getting past the bootstrap code too. It's really strange behavior.
 
So I reseated everything socketed and it actually boots past the copyright screen now. But like @rewrite it crashes after the copyright screen instead. It crashed on the high score screen first, then made it to the AMI logo before it crashed again. So we definitely have the same fault.

Edit: Burning another P1 ROM now to see if that makes it any better or if the same issue occurs. Could also be a bad socket or soldering on the socket or maybe even a dirty cart slot? Doesn't seem to affect normal games but maybe the repro carts are more sensitive to dirty slots?

Edit Edit: Burnt another P1 ROM, this is the third one I've tried. Same issue, I can coin up and start a game and it'll freeze randomly there, or during attract, it never makes the title screen during attract through it freezes on the high score screen or on the Presented by Cave logo. Once it made AMI but hasn't since.

Edit Edit Edit: After clearing the SRAM again it'll reach as far as the title screen occasionally and then freeze. If I coin up and start a game I can launch the game but then it freezes. It freezes after 10-30 seconds.
 
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So. Where do I start.
I get scrambled everything with espgaluda

LsoLQ66r.jpg
 
xodaraP said:
I also have no jumpers set in case that's a potential issue.
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For me J2 in (booting into trap romset) works fine for as long as the game is on, but no J2 (standard romset) has the same issues as you, except I'm around 90-120 seconds before crash. Whether it's playing the game or attract.

Thanks to @Mrhide I know it's not the file itself. And now that I'm also on my third eprom for P1, It's becoming less likely that that's the issue. I've checked for continuity everywhere off of P1 as well. Everything makes it where it should be and none of the pins are bridged.

Out of curiosity, do you too have v1 boards too?



I put together my other two sets, but apparently don't have any more 74ls138's so they're on hold and I can't test those yet. So just Ketsui for now.
 
I'll check. My sound worked without any modifications though so I think that means I'm on the later revision.

It has to be something to do with reading the data at the lower end of the address space if your Arrange version works fine on the same EPROM.

If the galuda main program ROM wasn't the full 32mbit already I'd double it and use the jumper to run upper address space to see if that helped.

I might try burning a Ketsui ROM and seeing if mine reacts like yours (it'll still run but with messed up graphics which is fine to see if/when it crashes at least)
 
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