pcb power issue from jamma

[purplec]

hi i have a multi game jamma board wich i have just recieved already installed in my first cab. i have since purchased a number of pcbs from ebay but when i install them on the jamma i get nothing, it sounds like the screen is on but no game.

would it have anything to do with the arcade power supply being modified. the multi game board gas its own atx power supply but there seems to be a power supply and a transformer in the unit.

any help would be greatly appreciated in distress at this point.

I have attached a pic of the internals the atx power supply is on the top for the multi board and then the arcade power supply is on the right (this powers up when the gamebox is on) on the left then is the arcade transformer i think.

any help would be greatly appreciated

thanks

[purplec]

any takers

when i remove the atx power supply and power up the jamma and the pcb, you can here the monitor power up and you can hear the low power supply powering up but i still can get the pcbs to work. i think they may be fried.

waste of money

[Spaz Monkey]

I'll bite.  Do you happen to have any other wires coming from/to the arcade monitor other than the power wires?

Typical power flow is:
Wall -> Power Supply -> Iso -> Monitor
               \------> Jamma harness

When powering on any game, do you hear any game sounds from the cab speakers?

[purplec]

a bite quick reelem in lol

yeah the power setup is as follows


                                                      ___ATX power supply for multi game
Wall -> switch->Power Supply ---[
                                                      ___DC power

                          \------> Jamma harness

I think thats how it is layed out. i got my hands on a multimeter and when i plug the tekken pcb into the jamma harness there is roughly 13 volts at the 12volt pin and 4.7 at the 5 volts. im gettin no monitor sounds, but it does work fine with the multi game pcb. hope i havent blown anything.

I appreciate your help thanks


Oh the pin outs for the multi game and tekken are different but just for the actual button inputs the power is the same, could this be the problem.

             

[CheffoJeffo]

i got my hands on a multimeter and when i plug the tekken pcb into the jamma harness there is roughly 13 volts at the 12volt pin and 4.7 at the 5 volts. im gettin no monitor sounds, but it does work fine with the multi game pcb. hope i havent blown anything.

Does the multi PCB run fine using the same power supply ?

FWIW, 4.7 sounds low to expect things to work ... is there a pot to adjust the voltage ?

[purplec]

yep it works perfectly, but not a sausage on the pcbs. im gonna do a full run through with the multimeter in the morning. Should i use the atx power supply from the multigame at the same time as the low power dc. any ideas what i should check for.

cheers for the replys

[SirPeale]

It looks like you have at least three power supplies there.  You need to figure out which one of those is sending current to your JAMMA harness.

I'm guessing your multi PCB gets it's power from one of the CD-ROM power connectors on the ATX PS?

[purplec]

The power supply on the bottom left of the pic is not working so its just the one on the right which I think is the supply that enables the DC to the jamma, and yes the multigame is powered by the ATX power supply. Im really confused about all this I thought it would be just a plug and play job but im determined to find the solution and would even consider rewiring hope it doesnt come to that though.

Cheers
Purplec

It looks like you have at least three power supplies there.  You need to figure out which one of those is sending current to your JAMMA harness.

I'm guessing your multi PCB gets it's power from one of the CD-ROM power connectors on the ATX PS?

[SirPeale]

Well, then the first thing to do it measure the output and input of that power supply.  Output first to see if it's putting anything out (which I'm betting it is not) and input to make sure it's actually getting power.

If it is...your power supply is dead, and needs either replacing or repair.

If it isn't...you need to find where in the chain your power supply lost it's AC source.

[purplec]

Hi ok so i removed one of the power supplys from the unit as it wasnt connected anyway, so all i have in their at the moment is the switcher and the atx unit which powers the multi game unit.

The whole cabinet has a little switch on the back that is powered from the wall power, when the switch is turned on the monitor can be heard powering up and you can also see the red led of the switcher coming on. I have checked the dc current from the switcher at the connected molex connecter and im defo getting  5 volts, 12 volts.

So before i start pulling my jamma harness apart should i check anything else also the -5volts is not connected. I`ve
attached a pic of the internals now, is it it okay just to have a switcher. And also what is the black item on the wires in the 2nd pic

cheers for all your help
purplec

[purplec]

here is a pic of my jamma harness does this look right im not sure about how the red 5volts are linked together. and does anyone know what kind of connector isused on the monitor in the second screen the green conector its got six wires.

[SirPeale]

 Check the voltage at the JAMMA harness.  If it's not getting to the harness, then it's not getting to your board.

[purplec]

OK so i got a new harness and just wired up the power terminals and connected a PCB and checked the voltages on the PCB and im getting 4.9 volts and the 12 volts so i think thats fine. Just a few questions

1) Would i get the voltages on the board if it was fried.
2) Should i use a molex connector to splice the 5 video cables to the monitor from my other harness so i can connect to the new as this works fine with the multigame board and i still wanna use it.
3) Should i be worried i was ripped off.
4) If anyone else that has a multigame board connected to their cabinet are you able to swap in new boards at will or do you have to modify the cabinet.

Thanks for your patience and help

Purplec

[SirPeale]

Turn your voltage up to 5.1VDC.

Yes, you'd still get voltage on a dead board if it were fried, unless it had total catastrophic failure.  IE the board was cracked in two or whatnot.  It's unusual to get *nothing* on screen.  Well...it would depend on the board, and the damage.  But I would imagine something would show up.  What is the board?  Are you sure it's JAMMA?

[purplec]

its a tekken 3 board and a soul edge board.