Pacman Cab with Jamma converter

[eccs19]

Not sure if there is an easy answer to this or not. I can get pics if anyone needs them.

I've got a Pacman cab that I'm working on bringing back to Pacman. It was converted to run horizontal games - 2 players, with a Jamma adaptor.  From what I've read, jamma is powered differently than the original Pacman board. (pacman has it's own transformer on the board)  If this thing has a jamma adaptor in it, does that mean someone re-wired the cab, or should I just be able to unplug the adaptor, plug in the Pacman, and away I go, or do I need to do some adjustments to the wiring hardness? Or is it not that simple, and I need to rewire the cabinet?

[RayB]

Posted here to avoid getting flamed on CGCC? 

If it's been converted to JAMMA, then just get a PAC to JAMMA adaptor and you're good to go.

http://www.mikesarcade.com/cgi-bin/store.pl?sku=PAC2JAMMA

[eccs19]

Posted here to avoid getting flamed on CGCC? 

If it's been converted to JAMMA, then just get a PAC to JAMMA adaptor and you're good to go.

http://www.mikesarcade.com/cgi-bin/store.pl?sku=PAC2JAMMA

Actually I posted here because there was something else that I had asked MS about, and he was worried that he sold me something that was not what I expected. I told him not to worry, I was expecting to get into this more than expected, but didn't want him to feel bad again.

You mentioned this converter, but the thing is that the cab already apparently has the pacman board plug, and a converter to convert it to Jamma.  I just want to know if I can just unplug this converter and plug in the pacman board, or would something else have been modified.  If I can just plug in the pacman board, and do some minor change back to the wiring, I would rather do that than spend another $50.

[eccs19]

Here are some pics of the existing wiring harness.

[RayB]

AHH!
Google for a JAMMA diagram and check to see which harness is JAMMA (the original one, or the adaptor)

[eccs19]

AHH!
Google for a JAMMA diagram and check to see which harness is JAMMA (the original one, or the adaptor)

Homework done.  Cab in NOT Jamma, but the adaptor is Jamma.  I also googled for pacman edge connector, and the cab does appear to be a actual pacman plug.

[eccs19]

Can I test the harness with out the PCB in it, and see what voltages are getting to the board to confirm if the wiring is still good, and has not been hacked for the Jamma? Anyone with links to show me what I would need to check? This may be the easiest way to confirm if this harness will be good or not.

[RayB]

Does the cabinet have a modern switcher power supply installed?

[eccs19]

Does the cabinet have a modern switcher power supply installed?

Hell, you got me on that one. 

Can you tell from the picture that i supplied? (2nd picture)

[NightGod]

That black box on the left side in the middle of the second pic is almost definately a switching power supply.

[RayB]

OK then, I am 90% sure that you CANNOT just plug your pac board in. As you already know, Pac boards take AC voltage and convert at the board.

It's really weird that they converted this to JAMMA and then still had an adaptor there... Maybe the first harness is some other common format, like Konami classic pinout...

[eccs19]

OK then, I am 90% sure that you CANNOT just plug your pac board in. As you already know, Pac boards take AC voltage and convert at the board.

It's really weird that they converted this to JAMMA and then still had an adaptor there... Maybe the first harness is some other common format, like Konami classic pinout...

So best bet may be to get one of those Jamma to Pacman converters, or prepare myself to rewire the cab. Hmm, hard call to make there. At least with the Jamma to Pacman converter, I can also use it for Jamma games if I really wanted to.

[SirPeale]

OK then, I am 90% sure that you CANNOT just plug your pac board in. As you already know, Pac boards take AC voltage and convert at the board.

This is true, BUT if you convert your Pac-Man to use a switcher, you *can* leave the board unmodified.

Heh...the only reason I know this is because I just did a lot of research on converting a Pac board from AC to DC.

You'll get better results if you make the changes to the board, but it's not 100% necessary.

[eccs19]

OK then, I am 90% sure that you CANNOT just plug your pac board in. As you already know, Pac boards take AC voltage and convert at the board.

This is true, BUT if you convert your Pac-Man to use a switcher, you *can* leave the board unmodified.

I think I would prefer not to mess with the board.  Do you have any good links or suggestions on this switcher?

My main goal here is to run Pacman. If the machine will never run a different game again, then that's great for me.  If I can just re-convert the wiring harness back to original, then that would be ideal. I'm not sure what would have been done originally to convert this thing to Jamma. I've seen online new wiring harnesses with the PSU included, and the PSU that is in those pictures "looks" like the one in mine, but I'm far from an expert, but I'm not afraid to poke around, checking voltages, etc. I just don't know where to start.  And I obviously don't want to plug in my pacman board and blow it up, just to "test".

[NightGod]

Grabbed this from a site if you are interested in converting to switching:

 Meanwhile, the Pacman modification is as follows:

   1. Jumper four wires over the AC->DC rectifier diodes (D3, D4, D7, and D8). The idea is to short 'em out; you won't be using them.
   2. Jumper a fifth wire across the large 4-ohm resistor by the heat sink.
   3. Pacman's 7.5V AC pin gets connected to +5V DC from the power supply.
   4. Pacman's GND pin (from the center tap of the 7.5V AC signal) gets connected to GND from the power supply.
   5. Pacman's 12V AC pin gets connected to +12 V DC from the power supply.

[eccs19]

Well after looking at the large picture of the pacman wiring harness here...

http://www.arcaderenovations.com/store/product.php?productid=313&cat=117&page=1

I have concluded that the original plug that is in the cabinet is the correct size for my Pacman board, but it is not wired the same. Most of the grounds are where they are supposed to be on my cabinet. I guess now the question that I have left remaining (not to you guy's, but myself), is should I rewire the cabinet, or use one of those Jamma to Pacman converters.  The question that I have about that, is will I have to convert my board to DC only, or do these converters take care of that for you?  I'll have to e-mail one of the manufacturers and see what they say. I just hope the Jamma conversion done on this machine is a good job, and not a hack. (I'm not that convinced that it's a good conversion quality conversion. I know the machine works with Jamma boards, so....

Thanks for listening.  lol

[RayB]

This is true, BUT if you convert your Pac-Man to use a switcher, you *can* leave the board unmodified.

But it looks like you already have a switcher style power supply in there. (The box on the left). The big thing at the bottom with the fuses, transformers, etc.. that's the original power supply, AC distribution, point, and isolation transformer for the monitor.

Confused yet?

[eccs19]

This is true, BUT if you convert your Pac-Man to use a switcher, you *can* leave the board unmodified.

But it looks like you already have a switcher style power supply in there. (The box on the left). The big thing at the bottom with the fuses, transformers, etc.. that's the original power supply, AC distribution, point, and isolation transformer for the monitor.

Confused yet?

Clear like mud.   

[Kevin Mullins]

Has there been any extra controls added to the cabinet? (extra buttons, joystick, etc)

It appears to me that they simply used the existing un-hacked Pac harness and made the adaptor to run Jamma boards. (the 44 pin connector is PAC)
The only thing really different is the added switching power supply that would have been necissary for the Jamma boards to run properly. It wouldn't be hard to "undo" the power supply part, but I'm certain there will be issues with the original one from it's Pac days. Probably better off leaving the switcher in there, but you'll need to absolutely verify the pinout on the 44 pin connector as to where everything is going and make sure it matches the Pac pinout.

Which side of the pcb does the black dot on the adaptor and such represent?

( Solder side = CKT / Component side = Comp  for this pinout link)
http://www.crazykong.com/pins/Pacman.pin.txt

[eccs19]

Has there been any extra controls added to the cabinet? (extra buttons, joystick, etc)

It appears to me that they simply used the existing un-hacked Pac harness and made the adaptor to run Jamma boards. (the 44 pin connector is PAC)
The only thing really different is the added switching power supply that would have been necissary for the Jamma boards to run properly. It wouldn't be hard to "undo" the power supply part, but I'm certain there will be issues with the original one from it's Pac days. Probably better off leaving the switcher in there, but you'll need to absolutely verify the pinout on the 44 pin connector as to where everything is going and make sure it matches the Pac pinout.

Which side of the pcb does the black dot on the adaptor and such represent?

( Solder side = CKT / Component side = Comp  for this pinout link)
http://www.crazykong.com/pins/Pacman.pin.txt

I was looking further, and I don't think that the original is wired the way it used to be. I think they completely rewired the cab to something else at some point.  I'll have to check further, but I think that I'm correct based on what I could see on the converter.  (Grounds don't match up)  When I got the machine it has 2 sets of controls with 3 or 4 buttons for each player.

[eccs19]

Anyone who was following this thread.  Here is info I found on the net.  It helps clear things up regarding if the Pacman is AC or DC.  Good read.

------------------------------------------------------------------------

Pacman/Ms.Pacman PCB Pinout.
Power supply: Pacman and Ms.Pacman get their input voltages from a 7 volt AC transformer. Once this power is on the pcb, it is converted to 5 volts DC (essentially the power supply is built-in to the logic board).

BUT you can hook up a standard switching power supply, which supplies 5 volts DC at 7amps (or greater) to the Pacman 7 volt AC input lines. This causes no problems. My only suggestion is that you turn the 5 volt adjuster all the way up on the switching power supply. This will make the output voltage from the switcher close to 6 volts. The Pacman logic board will process this voltage down to 5 volts thru it's normal AC to DC rectification circuit.

Another idea when using a switching power supply is to run jumpers over (or cut out) the two large rectifying diodes at D7 and D8 (essentially running the +5 volts switch power to component side pin E instead of C/D). Pin E (5th pin from left) is the 7 volts AC converted to DC (but not yet rectified). Just remember if the original Pacman PCB is put into a game without a switcher, obviously the board will not work.

Some people alternatively run the switcher's +5 volts to Pin 18 (solder side, pin right next to the 12 volts AC input) instead of pins C/D (component side). This skips the 5 volt rectification circuit completely and feeds the switcher's +5 volts DC directly to the PCB's 5 volt DC buss. Or a better way to do this is:

Cut or jumper over the two rectifying diodes D7 and D8 (large diodes just below the edge connector pins C/D).
Run a jumper from the component side edge connector Pin C and Pin D to the SECOND large trace just below it. This is the 5 volt buss. Note the top most trace just below the component side edge connector is ground. The large trace below that is +5 volts, and the next large trace (just above diodes D7/D is 12 volts.
Check for 4.95 to 5.1 volts at the ROM chips (pin 12=gnd, 24=+5v) and adjust the switching power supply as needed.
Obviously with this mod the Pac board won't work without a switching power supply. But it takes a lot of load off the switcher, connectors, and the Pacman board's 5 volt rectifying circuit if this modification is done.

After installing a switcher always measure the +5 volts on the PCB, preferably at one of the ROM chips (pin 12=gnd, 24=+5v). Or measure the +5 volts DC on the component side of the Pacman PCB (top most large trace is ground, large trace just below it is +5 volts DC). Adjust the switcher as needed to get 4.9 to 5.1 volts DC on the Pacman board.

wire | wire
Pin Componet side color | Pin Solder Side color
--- ------------- ----- | --- ----------- -----
A GND (center tap) R-B | 1 GND (center tap) R-B
B GND (center tap) R-B | 2 GND (center tap) R-B
C 7 volt AC Orange | 3 7 volt AC Orange
D 7 volt AC Green | 4 7 volt AC Green
E +7.5 vDC, unreg. | 5 Coin Meter in BLU-R
F speaker G-B | 6 reset W-B
H speaker R-Y | 7 Coin Meter out
J Coin mech switch O-G | 8
K Test switch O-W | 9 Credit switch R-G
L Select one player BR-B | 10 Select two player B-Y
M P1 move left Blu-W | 11 P1 move right Y-R
N P1 move up W-R | 12 P2 move up
P P2 move left | 13 P2 move right
R to GND for cocktail | 14 P1 move down BR-W
S RGB GND G-R | 15 GND for controls RED
T RGB Red R-W | 16 RGB Green W-BRN
U RGB Blue Y-B | 17 RGB Neg Sync O-R
V P2 move down | 18 (+5 volt DC out)
W 12 Volt AC B-W | 19 12 volt AC B-W
X 12 Volt AC Blu-Y | 20 12 volt AC Blu-Y
Y GND (center tap) Y-G | 21 GND (center tap) Y-G
Z GND (center tap) Y-G | 22 GND (center tap) Y-G

Note component letters G, I, O, Q are not used (they look too much like numbers).

[fredster]

I have made an adapter from bob robert's description.  I have purposely taken out all the guts inside of a PacMan cab and switched it to jamma. It's not a big deal really. There isn't much there.

(before the world comes down on me it was hacked to take a clone board and the other one I did was really water damaged)

I have all the parts. (the cable is cut up though)  It requires a special transformer assembly to give you all the voltages.  It's not really complicated.

But If it's working, I suggest you bolt everything back in, put the back back on the cabinet, and step away from the game except to play it.

You cannot hook that thing back up into the cab without having all the pieces. You will blow up stuff on the board you don't want to have fixed.

I don't think it means diddly squat to anybody if that thing is 100% original or not these days. As long as the outside of the CAB is good and the monitor is well maintained, the board and guts don't matter.

You will be better off making it 100% jamma in my opinion. If you want, you can buy some bootleg boards that play multigames on there for like $250. That will make the cab worth about $800.  An original Pacman in fair condition runs $300-$400.  It doesn't seem to matter at auction if they are original or not. 

[StephenH]

http://www.homearcade.org sells adaptors for Pac Man Boards to work on JAMMA Cabs. 

[RayB]

So eccs, is that adaptor you already have maybe all you need?

[eccs19]

So eccs, is that adaptor you already have maybe all you need?

Unfortunately not. I'm gonna need Jamma to Pacman board.