weird problem with MV-1F

Hey guys,

I was doing some work inside a friends conversion cab and I hit a snag. The original power supply shit the bed so I got a new power supply and installed it. It was playing boards fine, just wasn't getting sound. After doing some searching around the inside of the cab, I found the 12v line had been cut and taped to the inside of the cab, so I spliced in some wire from a spare jamma harness and ran the 12 volt to the power supply. Now here is my problem.. when I turn power on to the cab without the jamma harness hooked to anything, you can hear the power supply hummimg, but as soon as I hook it to the mv-1f the power supply dies. The power supply is putting out the correct voltage when unhooked, but when hooked up to the board all readings drop to zero. I have tested both the power supply and the board in my mvs cab and they both work flawlessly..so now Im stumped. Anyone have any ideas?

Thanks

-gordon

Try a new PSU?




UOMO TIGRE

all I can think of..

The first thing I'd do is go over the wiring making sure everything is where it's supposed to be set-up for the Jamma MV-1F..It sounds like something is backwards in the wiring..I'd be particular to check where the ground wires are located.
Check out the speaker/speakers making sure they are wired right..

Making sure the 12v line is in the correct side of the harness ..

Making sure the wiring is set up for MV-1F ..From looking ay Hard MVS it's a Mono set-up so I'd make sure the wiring to the speakers are set up to mono.
http://www.hardmvs.com/html/PCBcompare.htm

Turn off the cab...

Check continuity between +12, -5, +5v, and ground.

My guess is you have a short in the cab somewhere. Maybe between +12 and ground on the coin door.

RJ

channelmaniac said:

Turn off the cab...

Check continuity between +12, -5, +5v, and ground.

My guess is you have a short in the cab somewhere. Maybe between +12 and ground on the coin door.

RJ

Click to expand...

You hit the nail on the head once again RJ. I disconeccted the 12v and the cab fires up flawlessly. I checked the continuity and everything is fine, so I still have no idea whats causing it. However, cant i just buy a speaker harness for the MV-1f and splice the wires into the two speakers? That would still produce sound even if there is no 12 volt running to the board right? This cab will never be anything besides a neo, so running the 12v for other boards inst goign to be a big deal.

Thanks again for the help

-gordon

I forget what connections it has on it...

If it has the 4 pin connector for the speaker out then yes, you can use those.

However... you do need the +12v for the audio amplifier to work. The easiest thing would be to run a wire straight from the power supply to the MVS board and bypass the rest of the cab.

RJ

Alright cool..

any idea as to where I would run that 12 line to? Also, can you point me in the direction of a pinout for that 4 pin audio connector?

thanks
-gordon

double post

DecepticonZero said:

Alright cool..

any idea as to where I would run that 12 line to? Also, can you point me in the direction of a pinout for that 4 pin audio connector?

thanks
-gordon

Click to expand...

http://www.hardmvs.com/manuals/Jamma2NeoGeo4SlotPinout.pdf

http://www.hardmvs.com/manuals/MV-1FserviceManual.pdf

your the man..

thank you sir!