JAMMA board syncing fine on some cabs, but not others.

PCB problems and fixes
Post Reply
User avatar
matt5cott
Posts: 285
Joined: August 18th, 2008, 12:18 pm
Location: Nottinghamshire
eBay: matt5cott
Initials: MAT
Contact:

JAMMA board syncing fine on some cabs, but not others.

Post by matt5cott »

I've dug out a couple of my COMAD classic JAMMA boards (ahem :oops: :lol:)

Anyway, I'm looking to run these with a JAMMA switcher, long story short the boards work fine in a couple of my cabs, but not on the others I want to install them in :problem: (with or without switcher use, makes no diff)

Looks like a SYNC quirk as the picture is there but it's swinging about like Linford Christies dick in a sprint :palm:

Suggestions? Voltages seem OK.

Trying couple of things from wiki now,

Check the power supply again, some older boards require their 5Vs to be more like 5.2V. - Had it up near 5.2v. no difference.
Check whether your board requires -5v or not - some old boards did. - Ran fine on my MVS cab with JAMMA converter, has no -5v connected to PSU.

Thanks for reading :)
Last edited by matt5cott on November 24th, 2022, 4:28 pm, edited 3 times in total.
ImageImageImage
User avatar
yosai
Windy City
Posts: 4000
Joined: August 17th, 2008, 5:00 pm
Location: London
eBay: yosai

Re: JAMMA board syncing fine on some cabs, but not others.

Post by yosai »

Video ground connected?
User avatar
matt5cott
Posts: 285
Joined: August 18th, 2008, 12:18 pm
Location: Nottinghamshire
eBay: matt5cott
Initials: MAT
Contact:

Re: JAMMA board syncing fine on some cabs, but not others.

Post by matt5cott »

yosai wrote: November 24th, 2022, 4:08 pm Video ground connected?
It's on the JAMMA edge but tracing it all the way into the machine will be a hassle, though it seems there's no harm in jumping it on the board from 14 to normal ground as per here viewtopic.php?t=17430 so I will give that a bash, thanks 8-)
ImageImageImage
User avatar
matt5cott
Posts: 285
Joined: August 18th, 2008, 12:18 pm
Location: Nottinghamshire
eBay: matt5cott
Initials: MAT
Contact:

Re: JAMMA board syncing fine on some cabs, but not others.

Post by matt5cott »

Hrm, wired pin14 videoground to the normal ground and it improved things, less roll, but still rolling and not working correctly :wtf:

Also tried a specific cable wiring 14 to the "proper" Ground coming into the machine, same as above.
ImageImageImage
Post Reply