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ekorz

Multi Boyz 4 Pi
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Ok I know someone out there has awful taste like me. I got a nonworking SFTM rom board that was blowing fuses and realized some jerkface removed the oscillator at X1 on the rom board. Right above the dips. I can't for the life of me find a good enough photo online to tell the speed. My Golden Tee's run a 4mhz crystal there but I'm not sure that'll work since this rom rev is very different. Anyone got one they can check? Maybe help me out with a nice high-res photo just in case the same jerk took more stuff off this thing? Thanks!!
 
It's a 4MHz indeed.
 

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bummer, popped in a 4mhz crystal from another board, but it's still blowing fuses. Anyone have any ideas? Thankfully there's not a lot on this board, I just can't think why it would blow a fuse on the main board.

...or high res pics of the rest of the rom board, so I can tell if something else is missing/off
 
I can take some more pics in about 12 hrs. Shame there's a 1Mb limit on images here, might have to link them off-site.
 
I can take some more pics in about 12 hrs. Shame there's a 1Mb limit on images here, might have to link them off-site.
thanks! offsite is fine. i use imgur or google drive, or i can pm you my email.
 
thanks for the pics. unfortunately I can't find anything else missing. Anyone have any idea what would cause a fuse to blow? Fuse is connected to the 5v (pin 3 & 4) on the jamma edge. the motherboard works fine with another rom board so I'm guessing it's the rom board. Am I looking for, say, a 5v pin on something bridging with ground? Bleh, I have no more ideas... and only 7 more fuses!

edit: actually, weird @fluxcore does yours boot on that motherboard? mine has U31 and U30 populated with VRam there. I wonder if that actually matters...
edit2: removed them, because. still blows fuses.
 
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Sure does. I presume you've checked for shorts etc?

Does it still pop when you remove the top two boards? Might be able to isolate it like that...
 
it's a bottom board from a Golden Tee 3d. Maybe there's more to it than the part number being the same. Anyway it only blows a fuse when the SFTM rom is on. I can boot it fine with Golden Tee. I'm not even using a sound board to test since Golden Tee seems to boot without it.

About checking for shorts, yeah that's what I'm trying to figure out I guess! How would a short on the rom board manifest.. just something showing continuity with a 5v that shouldn't be?
 
is there a power regulator on the sub-board? or an amp, or anything else that generates a lot of heat? those are the most likely culprits for a short. After that any inductors or filter caps maybe?

you could also try pulling all socketed chips and see if the short occurs to help narrow it down.
 
is there a power regulator on the sub-board? or an amp, or anything else that generates a lot of heat? those are the most likely culprits for a short. After that any inductors or filter caps maybe?

you could also try pulling all socketed chips and see if the short occurs to help narrow it down.
Twisted wins! See, this is why I try to restrict myself to only working on bad fighting games... I had just installed a row of roms backwards. :thumbup:
 
Haha! nice.

One of my friend's rando broken boards had a whole 64dip CPU soldered in backwards. That made me chuckle.
 
We should start a thread with the common mistakes not to make like (with pics would be great):
- components installed backwards in sockets
- boards plugged without adapter due to the edge connector being JAMMA "compatible" (Capcom Classic, Sega System 16 & 24, etc.)
- boards plugged backwards because the smaller rom board isn't on the top of the stack as "expected" but in fact at the bottom (Data East MEC-M1 hardware, Irem M92, etc.)
- 1Mb EPROMs fuckery (27C100/27C1000/27C1001/27C010) with the most confusing device naming in EPROM history (some 27C1000 being JEDEC, others not).
- Classic PCBs powered without all three voltages (+5V, +12V, -5V). Yes, none of them is optional and are actually used by vital components like the CPU and RAMs on early games (Space Invaders and its famous 16 RAMs failure...)
- etc.
 
I do a lot of troubleshooting work right next to my test rig, so my favorite bonehead move is this...

I wrap up some piece of work, then power up my supergun.. and am rewarded with a black screen because I haven't actually plugged in my pcb yet.
 
I must admit while repairing MVS slots I sometimes inadvertently switch on dipswitch 8 (freeze mode) and I'm greeted with a black screen which is not good for my heart, especially when the board was working mostly fine a minute ago.
 
I do a lot of troubleshooting work right next to my test rig, so my favorite bonehead move is this...

I wrap up some piece of work, then power up my supergun.. and am rewarded with a black screen because I haven't actually plugged in my pcb yet.
I have a similar setup and have done this more than once
 
I'm not ashamed to admit I loved SFTM in the arcade back in the day. :D

if I ever find a PCB for a reasonable price I'll pick it up. I have no idea why they go for so much for a game that everyone snubs their nose at.
 
I have 2 SFTM pcbs and also have it on my Sega Saturn and PS1. I like the game . The only thing with the pcbs is you need the special kick harness.
 
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