Galaga bootleg damaged eprom / unknown error

jpx72

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Hello
My galaga bootleg has damaged eprom (3,7,8,9) and I have tried to replace it, but my eproms are marked from No. 1 to 10 photos here:
http://imgur.com/a/ZAdZO
and I am lost in identifying which files from Mame set should go where.

Also I haven't found correct schematics for it anywhere, only one pinout of my main connector was correct, the one on page 3 of this file:
https://www.arcade-museum.com/manuals-videogames/G/Galaga misc.pdf

Anyone solved this problem before? Thanks!
 
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Thank you very much for identifying the type.
But I also need to know which file dump goes to which eprom, since 4 eproms are dead.
I have to program 4 new eproms, but there are much more files inside MAME's galaga.zip
I know it has to be 4kbytes each.
 
I don't think the Galaga ROM set will work directly on the Nebulous Bee bootleg PCB. I think you need to download the nebulbee set, which looks to have 3 different ROMs (labeled .01, .02, and .04). Then maybe the others go by the regular Galaga ROM numbering?

It looks like MAME removed Nebulous Bee in the current driver, but it was in the old MAME: https://github.com/neonichu/iMame4All-for-iPad/blob/master/src/drivers/galaga.cpp#L647 , which looks like it used a lot of the same ROMs as the regular set. Unfortunately, the ROM names have changed, and finding ROM sets to really old MAME versions is kinda difficult, so you might want to cross reference with the current MAME: https://github.com/mamedev/mame/blob/master/src/mame/drivers/galaga.cpp#L2344 .

DogP
 
Thanks, I will try to investigate.

Or does somebody have rom dump of the number 3 eprom?
I think the rest should be ok...
Thanks
 
The #3 EPROM should be the same as the gg1_3.2m file from the Galaga MAME ROM set.

DogP
 
For future reference I have done a bit of comparison of my dumped roms and galaga.zip from 0.184 mame set.
My eproms may be damaged so the differences may be caused by this fact.

#1 gg1_1b.3p
#2 gg1_2b.3m
#3 gg1_3.2m difference in 260 bytes
#4 gg1_4b.2l
#5 gg1_5b.3f difference in 30 bytes
#6 ?
#7 ?
#8 gg1_9.4l
#9 gg1_10.4f
#10 gg1_11.4d

File gg1_7b.2c is totally different from #6 and #7.
I don't know how to find the #6 and 7, don't know if they are not dumped badly because of the damage.
 
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Hey thanks I have identified the 6 and 7th eprom, the 7th wasn't in the 0.184 mame galaga set, but I have found it in 0.37 galaga84.zip

I have replaced the damaged eproms and now I hav some success. I know the pcb troubleshooting is not possible when you don't have the board in hands, but if somebody can give me a hint on what can be wrong, it will be great:
https://youtu.be/1I11hcxqCXk
This video is showing a loop that is happening on my board. I can see a test screen inbetween showing ram&rom OK, but the game won't load.
 
The credit system doesn't have any effect, or any dip switch in this row of switches.
But when I switch all the switches on the second dip switch row ON, it locks on the test screen, the number at SOUND keeps changing randomly every second or two. Meanwhile you can change the credit system and see the changes on screen.
 
Sounds like either stuck inputs, or the code roms for the 2nd z80 are bad. I'll check tomorrow to see if i have a working pcb, or maybe a dump of the correct roms.
 
Hmm I think I have the right roms now, but I would like to compare my dumps with a full set from a working board.
Can't see anything on the input side wrong...
 
Check your 'FREEZE' dip, if it is on during bootup, you get the results you are seeing, rebooting over and over. Also, I sent you a PM with the CRCs to check you roms with.

- Mike-
 
Thanks the Freeze button works as said.

But the bad news is that although I have compared my dumps with the correct ones, foumd some discrepancies and reprogrammed the wrong eproms, I am still stuck on the same image (see video).
So the problem is elsewhere, shame that I cannot use original schematics to search for problems.
Well I will try to search for other damage, but I am not giving it much hope...
 
Thanks the Freeze button works as said.

But the bad news is that although I have compared my dumps with the correct ones, foumd some discrepancies and reprogrammed the wrong eproms, I am still stuck on the same image (see video).
So the problem is elsewhere, shame that I cannot use original schematics to search for problems.
Well I will try to search for other damage, but I am not giving it much hope...
Take a look at the schematics on my manuals page, Gallag green board.
 
Thank you very very much for your help, I have downloaded the schematic and will try to figure something out.
Will update thread when I'm succesfull.
 
Hello guys!
I just returned to say that finally a friend of mine who knew what he was doing with an osciloscope was able to return this board back to life!

The main problem weren't any bad components, only dirty/oxidised contacts.
Cleaning wasn't enough, replacing Eprom sockets solved the problem.

Thanks Thomas from www.8bit-homecomputermuseum.at !!!
 
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