Space Demon / Space Firebird PCB repair help

smalltownguy2

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Hi all,
I'm finally taking the time to dig into getting the Space Demon mini cab that I laid hands on last summer working again. I was able to procure a few board sets, but both are in need of repair.

I purchased a semi-working Space Firebird boardset on feeBay a few months back, but it has missing sprites and seems to want to freeze during attract mode.

Also, big thanks to Mongo for sharing his Space Demon boardset with me. It's non working, but hopefully I'll be able to use it to assist in my repair.

From what I understand (reading in the KLOV databse), space Firebird was the parent of Space Demon, with Space Demon being a clone licensed by Fortrek from Nintendo. Since all of the connectors and hardware for this cabinet and game resemble early Donkey Kong wiring, this is consistent from what I've read.

I have a complete working power supply and harness for this game, so now I can get to working on the 2 PCB sets I have.

Where to start? Here are the 2 videos showing what the 2 boards are doing out of the box, right now. The 1st video is my Space Firebird board - it boots, but there are missing graphics, and it freezes during attract mode. The 2nd video is Mongo's Space Demon board - as you can see, it boots to garbage.





A few pics of Mongo's boards:

attachment.php



attachment.php
attachment.php


As I understand it, the top board pictured is the audio board, the middle picture is the CPU board, and the 3rd picture is the graphics board. Is that correct?

Comparing Mongo's board to my own, they appear identical. I read online that a few other people have successfully converted a Space Firebird PCB to a Space Demon PCB by swapping roms, so that's what I'd like to try to do. But first I need to get a fully working boardset. I figure since the Space Firebird board set is working a bit better, I'd start with that set first.

Tools I own:


  • DMM
  • Logic Probe
  • Rom Burner (have not used much, though)
  • Rom eraser
  • various soldering paraphernalia (irons, desoldering gun, jumper wire, etc)
  • Chip extractor
  • test bed with spare fully working (100%) Sanyo 20EZ monitor
  • lots of tenacity and patience
I'm open to all guidance and suggestions. What next?
 

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One of the first things I would try is other/new ribbon cables. The missing sprites is usually a bad ram chip or supporting chip. Could also be a bad connection.

EDIT:

That video makes me think there is a heat/power problem. Power supply or board is heating up causing an open or short then restarting. Try to put a load on the power supply (without you pcb) and monitor the voltages. You should load all of the power supply voltages with something. You can use a simple light bulb for each output and will give you a visual of which is failing or if all are failing.


Hi all,
I'm finally taking the time to dig into getting the Space Demon mini cab that I laid hands on last summer working again. I was able to procure a few board sets, but both are in need of repair.

I purchased a semi-working Space Firebird boardset on feeBay a few months back, but it has missing sprites and seems to want to freeze during attract mode.

Also, big thanks to Mongo for sharing his Space Demon boardset with me. It's non working, but hopefully I'll be able to use it to assist in my repair.

From what I understand (reading in the KLOV databse), space Firebird was the parent of Space Demon, with Space Demon being a clone licensed by Fortrek from Nintendo. Since all of the connectors and hardware for this cabinet and game resemble early Donkey Kong wiring, this is consistent from what I've read.

I have a complete working power supply and harness for this game, so now I can get to working on the 2 PCB sets I have.

Where to start? Here are the 2 videos showing what the 2 boards are doing out of the box, right now. The 1st video is my Space Firebird board - it boots, but there are missing graphics, and it freezes during attract mode. The 2nd video is Mongo's Space Demon board - as you can see, it boots to garbage.





A few pics of Mongo's boards:

attachment.php



attachment.php
attachment.php


As I understand it, the top board pictured is the audio board, the middle picture is the CPU board, and the 3rd picture is the graphics board. Is that correct?

Comparing Mongo's board to my own, they appear identical. I read online that a few other people have successfully converted a Space Firebird PCB to a Space Demon PCB by swapping roms, so that's what I'd like to try to do. But first I need to get a fully working boardset. I figure since the Space Firebird board set is working a bit better, I'd start with that set first.

Tools I own:


  • DMM
  • Logic Probe
  • Rom Burner (have not used much, though)
  • Rom eraser
  • various soldering paraphernalia (irons, desoldering gun, jumper wire, etc)
  • Chip extractor
  • test bed with spare fully working (100%) Sanyo 20EZ monitor
  • lots of tenacity and patience
I'm open to all guidance and suggestions. What next?
 
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One of the first things I would try is other/new ribbon cables. The missing sprites is usually a bad ram chip or supporting chip. Could also be a bad connection.

EDIT:

That video makes me think there is a heat/power problem. Power supply or board is heating up causing an open or short then restarting. Try to put a load on the power supply (without you pcb) and monitor the voltages. You should load all of the power supply voltages with something. You can use a simple light bulb for each output and will give you a visual of which is failing or if all are failing.


Oh, sorry, I wasn't clear: in the videos I shot, I cut the power to the boards several times to reset them. So that's not a power supply problem, that was me switching it on and off :D

But you DO bring up a good point, I will load the PS tonight and test voltages to make sure they're a-ok.

I found the Space Firebird manual, so I will use that to get my voltage measurements.

Also, looking more closely at the pics of Mongo's board, I see the labels on the eproms indicate 'TST' which crosses to 'Space Firebird - Sega Gremlin' on Mike's website:

http://www.mikesarcade.com/cgi-bin/spies.cgi?action=url&type=info&page=NintendoList.html
 
I suspect bad ram. For kicks, I tried swapping each socketed chip on my boards with Mongo's boards.

Bad news: no change.

Good news: no change!

This tells me that all the EEPROMS, Z80, and other socketed chips are all OK, since they each behave the same on each board set. The problem must lie in a chip that's soldered to the board.

Swapped a bunch of ribbon cables too, and no changes. So I believe they're OK.

So, I've got one boardset (mine) that boots partially, then freezes. And another boardset (Mongo's) that won't boot.

I tried swapping Mongo's sound board into my set, and found something interesting: the boardset acted the same -- froze during attract. BUT...there was no starfield. Interesting....apparently the starfield is contained somewhere on the sound board. That would explain why Mongo's boardset boots to a black screen with garbled graphics. I should probably boot his board set with my sound board to see if I get a starfield with garbage. That would confirm that.

Next I tried swapping Mongo's video board into my set. Everything acted the same - game came up with the same missing characters, and froze during attract. So, that tells me that Mongo's video board should be good, as well as mine.

What's that leave? The CPU boards. Mongo's won't boot at all, and mine only boots partially.

That's why I suspect bad ram. So, how do I check ram? Can I probe it with my logic probe? Ballytablewiz tells me I can just start touching chips to see which ram chips aren't warm. The cool ones aren't running. I've attached a picture of my CPU board. Which chips are the ram chips?

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Well, wouldn't you know...I plugged my sound board into Mongo's board set and voila, starfield appeared. Still a screen full of garbage graphics, but at least it's a starfield background with garbage graphics.

That confirms it - the starfield is contained somewhere on the sound board. Or at least the processing of the starfield is. And Mongo's sound board is broken in that area too.

So now I've ID'd at least 2 issues on Mongo's board set: a CPU board problem, and a sound board problem.

OK, I'm off to bed now. We'll see if I get any divine inspiration in my dreams.
 
Found some good info today on Brasington's site. A chart listing all of the chip mappings for the Kong 2 and 4 board sets. Though I'm sure things will be a bit different on my Space Firebird board sets, this should prove useful in narrowing down what chips do what on my boards:

chipmap.jpg
 
OK, bumping this back up again. Thanks to darthi8nt, TWO space firebird board sets have been repaired. So, now the intention is to convert one of them into a Space Demon with ROM swaps. Here's a good info page I found on each game:

Space Firebird

Space Demon


According to each of those sheets, the boards are identical in their builds. Theoretically, it should be possible to swap out 8 eproms on the CPU board (all 2716's), 1 eprom (2708 chip), 2 eproms on the video board (2716's) and one prom chip at 3N on the video board (32 bit prom).

These 2 boards are currently being benched by darthi8nt, and he's successfully burned all the eproms (10 2716's total) but we're having trouble with the 2708 eprom from the sound board, and the 32 bit prom from the video board. We had steph from hobbyroms burn us a prom for 3N, but the board won't boot with all the SDM roms inserted with that prom. I suspect that either the 32 bit prom or the 2708 eprom (chip 20 from the sound board) is not correct. Unfortunately, neither darthi8nt nor myself have the capability to read *or* program to these types of chips. Does anyone else here have the ability to work with these older types of chips that would be willing to lend us a hand?

I'm suprised that my Needham EMP-10 cannot burn to a 2708 eprom, seeing how old it is. It just doesn't show up on my list.

Darth can probably chime in here on the type of chip at 3N on the video board, as to the type of prom it is.
 
You just need an older EPROM programmer. ;)

I keep a Data I/O Series 22 around just for those pesky ancient chips.
 
Its all good to go. Had to double burn the eproms and verify them I found someone to burn the sound 2708 Eprom for me I'll be sending both boardsets out WED.

here is a video of Space Demon running
http://youtu.be/rGKMfL3blH0
 
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HOLY SHIT you did it!!

Yee HAW!!

Amazing. AMAZING!!!!!!

Man oh man, after a year of testing, searching, learning, asking, begging, looking some more...

A working Space Demon boardset means I'm just THAT much closer to finishing the project that I'd thought would NEVER get done.

Thank you so much!!

:notworthy: :notworthy: :notworthy: :notworthy: :notworthy:
 
so, were you able to convert a space fire bird to a space demon? I'd love to pick up a set of roms so I could play that on my cocktail for a while- SD is just so much cooler than SFB (IMO)
Congrats on getting it fixed, now you just need a coin door ;)
 
I'll know in about 2 days, when the boards get here. There was a single 2708 eprom that darthi8nt couldn't burn yet, so he had someone else burn it for me and ship it to me directly. That should get me sound, and a fully working Space Demon.

As far as I know, it will only be the 2nd working Space Demon in existence, besides Todd Tuckey's.

*fingers crossed!*
 
Well, thanks to Todd Tuckey, we now have video goodness of a working Space Demon. This will be VERY helpful in putting the finishing touches on the TST-Fortrek board conversion.

Here's a video Todd took of his Space Demon mini - the only currently working Space Demon in the world that I know of. (and Todd, for that matter):



Darthi8nt has been working diligently along with myself to pull this off....the problem we have with the board conversion is that we can't use the MAME romset to burn the roms for this game, because we believe whomever dumped these roms BITD dumped the sound eprom incorrectly.

We figured this out when I had Steph from hobbyroms burn us a 2708 eprom for the ESS board to finish off the Space Demon coversion. When I fired up my board set, all seemed fine until I coined up and started a game. As soon as I got control of the ship, the screen flashed blue and stays with a blue hue until you blow up. Then the screen returns to normal. The boardset was acting just like it does in MAME. Darthi8nt and I already know that there are graphics handled by that 2708 chip (namely the starfield background, for one) so we suspected a bad rom dump in the MAME romset.

The only option in correcting the issue was to get our hands on an ACTUAL Fortrek board set. Not exactly an easy feat, by any means. The last Fortrek board that came up for sale was 3 years ago, and guess who bought it? Yep, Todd Tuckey :)

To be sure that our theory would test out, we asked Todd to shoot us a video, proving that the game did NOT in fact have blue screen during gameplay. This video confirms it. There is something wrong in the rom images used for MAME that does NOT happen on an actual Fortrek board.

Well, after some searching, it seems we've been able to procure a dead Fortrek boardset, so here's hoping the ESS board eprom 20E has survived the test of time. We hope to dump the contents of that 2708 eprom and test it with the rest of the Space Demon eproms on a working Fortrek OR TST board to see if the board looks/plays like Todd's.

Thank you very much to Todd Tuckey for shooting that video!
 
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