Street Fighter 2 Bootleg
- Thread starter Dean F
- Start date
A photo of the PCB would be a good start.
Have you reseated the EPROMS & other socketed ICs?
Are there dip switches and is one a test mode?
After that you could start by pulling the EPROMs and verifying them.
Be sure to visually inspect both sides of the PCB looking for anything obvious (missing CPU, broken components, cut tracks, burnt ICs, battery damage, rust etc).
Are there any sounds or beeps at boot? When you press buttons?
Nes4life2020-06-30 10:17:26
Have you reseated the EPROMS & other socketed ICs?
Are there dip switches and is one a test mode?
After that you could start by pulling the EPROMs and verifying them.
Be sure to visually inspect both sides of the PCB looking for anything obvious (missing CPU, broken components, cut tracks, burnt ICs, battery damage, rust etc).
Are there any sounds or beeps at boot? When you press buttons?
Nes4life2020-06-30 10:17:26
First thing i would do is check the 10Mhz crystal is giving a 10Mhz signal (near to the 68000 CPU in the top right). Then I'd check the contents of the eprom near the edge connector (because I like checking Eproms anyway
).
I'd try and find another picture of this PCB online and see if the 7407 at U216 and U215 were optional or have been pulled out and now need replacing.
Definitely reseat all socketed ICs as that's something anyone can do and can have quick results. Be careful not to break any legs and definitely put them all back the right way around.
There's a lot of dips in the top right but i doubt you'll find a document that outlines the settings to see if one is a test mode (maybe you'll be lucky with a google search).
If there's nothing else that's obvious (ripped out ICs or broken traces) I'd then look at the data line and address line activity on the 68000 CPU at boot. See if any are floating or stuck.
After that it's testing the CPU-accessible RAM and ROM.
If this is the first PCB you've attempted to fix then you might be in at the deep end!
Nes4life2020-07-01 23:00:28
I'd try and find another picture of this PCB online and see if the 7407 at U216 and U215 were optional or have been pulled out and now need replacing.
Definitely reseat all socketed ICs as that's something anyone can do and can have quick results. Be careful not to break any legs and definitely put them all back the right way around.
There's a lot of dips in the top right but i doubt you'll find a document that outlines the settings to see if one is a test mode (maybe you'll be lucky with a google search).
If there's nothing else that's obvious (ripped out ICs or broken traces) I'd then look at the data line and address line activity on the 68000 CPU at boot. See if any are floating or stuck.
After that it's testing the CPU-accessible RAM and ROM.
If this is the first PCB you've attempted to fix then you might be in at the deep end!
Nes4life2020-07-01 23:00:28
rockbottom
User
I've fixed loads of these over the years, in addition to other suggestions:
1. turn all dips off
2. try swapping the socketed 62256 rams u197, u223, u57, u58. I've had those exact Winbond chips fail more than once.
3. dump the socketed main 68k program roms u196 and u10, compare with mame, dump u196 as 27c800, u10 as 27c2100 or 27c400 and split. DO NOT dump u10 as anything Jedec pinout (27c2048/27c220/27c4096 etc.) you might kill it
4. reprogram palce/gal u104. I've had issues with that more than once (no boot/black screen), bizarrely every time the chip had been corrupted somehow rather than failed, so erase/reprogram, no need to replace. The image is in mame.
5. On these boards the the hacks are done by overlaying additional code over the main roms. this is done by the big 27c220 eprom next to the jamma conn and the "patch" palce/gal marked "44". it's possible to revert the hacks by removing those 2 chips, then doing a small mod on the pal socket (fit few small wires/links), details of mod are in mame source cps1.cpp. This will rule out those two parts and depending on your preference you may want to keep the game in this state anyway, if you prefer the game unhacked. You can also dump those 2 parts and compare with mame.
Anything other than the above is unusal in my experience, it's usually all gfx problems with these given that about 80% of the whole board is gfx generation. Don't be suprised if you get it running and then have gfx issues too
Ignore the missing 7407's and resistors for now, the bootleggers scrimp on the vdac fade channels, so the colour fade in/out effects between fights etc. don't work. It's possible to fit the parts and get it working. There's also few bootlegger cock-ups in the analog sound section, which can be sorted out to improve the sound quite a bit.
These are fun boards to play with, good luck
Edit:
Um, well I just noticed last post was over a year ago, I guess there's not much action in "technical" these days
But then why's it in Pinball technical anyway? I'll assume you've moved on one way or another since then... still perhaps useful info if others come looking.
rockbottom2021-07-19 00:51:12
1. turn all dips off
2. try swapping the socketed 62256 rams u197, u223, u57, u58. I've had those exact Winbond chips fail more than once.
3. dump the socketed main 68k program roms u196 and u10, compare with mame, dump u196 as 27c800, u10 as 27c2100 or 27c400 and split. DO NOT dump u10 as anything Jedec pinout (27c2048/27c220/27c4096 etc.) you might kill it
4. reprogram palce/gal u104. I've had issues with that more than once (no boot/black screen), bizarrely every time the chip had been corrupted somehow rather than failed, so erase/reprogram, no need to replace. The image is in mame.
5. On these boards the the hacks are done by overlaying additional code over the main roms. this is done by the big 27c220 eprom next to the jamma conn and the "patch" palce/gal marked "44". it's possible to revert the hacks by removing those 2 chips, then doing a small mod on the pal socket (fit few small wires/links), details of mod are in mame source cps1.cpp. This will rule out those two parts and depending on your preference you may want to keep the game in this state anyway, if you prefer the game unhacked. You can also dump those 2 parts and compare with mame.
Anything other than the above is unusal in my experience, it's usually all gfx problems with these given that about 80% of the whole board is gfx generation. Don't be suprised if you get it running and then have gfx issues too
Ignore the missing 7407's and resistors for now, the bootleggers scrimp on the vdac fade channels, so the colour fade in/out effects between fights etc. don't work. It's possible to fit the parts and get it working. There's also few bootlegger cock-ups in the analog sound section, which can be sorted out to improve the sound quite a bit.
These are fun boards to play with, good luck
Edit:
Um, well I just noticed last post was over a year ago, I guess there's not much action in "technical" these days
rockbottom2021-07-19 00:51:12
rockbottom
User
Well personally I like these because the lack of custom chips means they can always be repaired. This is in sharp contrast to official cps1 boards which as we all know the cps-A custom chips die then they're unrepairable. I've got a boards I've had for over 20 years which to this day still cannot be fixed due to that custom chip
These bootlegs only have pals/gals and most are dumped nowadays so they can live forever, well at least as long as 74 logic chips and pal/gals remain available.
Also they're cheap, common enough, good for noobs to play with, who cares if a bootleg gets damaged by bad repair attempt
These bootlegs only have pals/gals and most are dumped nowadays so they can live forever, well at least as long as 74 logic chips and pal/gals remain available.
Also they're cheap, common enough, good for noobs to play with, who cares if a bootleg gets damaged by bad repair attempt
rockbottom said:Well personally I like these because the lack of custom chips means they can always be repaired. This is in sharp contrast to official cps1 boards which as we all know the cps-A custom chips die then they're unrepairable. I've got a boards I've had for over 20 years which to this day still cannot be fixed due to that custom chip
These bootlegs only have pals/gals and most are dumped nowadays so they can live forever, well at least as long as 74 logic chips and pal/gals remain available.
Also they're cheap, common enough, good for noobs to play with, who cares if a bootleg gets damaged by bad repair attempt
For sale
Dave.