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Software Support => GroovyMAME => Topic started by: Rustler77 on April 15, 2019, 08:27:24 am

Title: JPAC video quality issue, I think
Post by: Rustler77 on April 15, 2019, 08:27:24 am
Hi Everyone

My MAME cab has always been very hard to look at, the image is really unstable and has a sort of horizontal gitter to it. I always thought my chassis just needed a service but then I connected an MVS with Metal Slug X and the picture is really stable.
I'm using:
- Win 7
- HD5450
- CRT Emudriver 2.0_beta_15_12.6_W.7.8.10-64
- JPAC into the Astrocity cab.
I've made a comparison video, the focus is a bit dodgy but you can see what I'm talking about. https://drive.google.com/file/d/1arhz3nwz2x3JenxZBZ0DQV25MXm_5Kp4/view?usp=sharing (https://drive.google.com/file/d/1arhz3nwz2x3JenxZBZ0DQV25MXm_5Kp4/view?usp=sharing)
Would love to know how to fix this if anyone has any ideas.

Cheers, Ben
Title: Re: JPAC video quality issue, I think
Post by: piensken1 on April 16, 2019, 12:24:56 am
Hey,

Did you test other roms?

I have more or less the same issue.
But sunset riders are running perfect en others not.
Title: Re: JPAC video quality issue, I think
Post by: Rustler77 on April 16, 2019, 12:52:54 am
Yep, on all ROMs. I used Metalslug X because it was the only real arcade hardware I had for comparison.
Not sure about Sunset Riders though, I'll check it  tonight.

Sent from my Nokia 6.1 using Tapatalk

Title: Re: JPAC video quality issue, I think
Post by: Sledge on April 16, 2019, 02:10:19 am
And i assume you've tried adjusting the sync pots etc?
Title: Re: JPAC video quality issue, I think
Post by: piensken1 on April 16, 2019, 02:29:21 am
thats also maybe an option.. :) with me its only at some games.. some run more then perfect, others just not :p
Title: Re: JPAC video quality issue, I think
Post by: Rustler77 on April 17, 2019, 06:33:22 am
piensken1 - Sunset Riders is no different than the others for me.

Sledge - I haven't adjusted the sync pots, I didn't realize that was some thing that needs to be done when swapping out PCB's. Its a bit of a mission to get to the back of my cab but I'll give it a go.
Title: Re: JPAC video quality issue, I think
Post by: keilmillerjr on April 17, 2019, 07:47:59 am
I actually found out i was adjusting the pots a lot, and it was a bad remote control board.
Title: Re: JPAC video quality issue, I think
Post by: Rustler77 on April 19, 2019, 06:05:46 am
I have a Nanao MS8-29FSG.  I don't think it has a pot to adjust the sync, if it does I can't find it.

It was suggested to someone on a different forum with a similar sounding problem that the MAME PC needs to be grounded to the JAMMA harness. I'm in Australia so my Astrocity has been fitted with a 240-110V step-down transformer and my MAME PC gets power from the back of the cab before it hits the step-down.

Also, sometimes I get a decent tingle from the JAMMA harness or the ground shields of things connected to it.  I might have a bit of an earth leak or something, not sure if this would have anything to do with my video problem?
Title: Re: JPAC video quality issue, I think
Post by: Mike A on April 19, 2019, 07:23:44 am
Bad grounding can cause all sorts of weird problems. You should get that sorted out first. Once that is good your problem may be solved, or at least that will be a check off of the list of possible problems.
Title: Re: JPAC video quality issue, I think
Post by: Rustler77 on April 22, 2019, 06:06:11 am
Had my electrician brother and his multimeter around over the weekend. He pointed out that the power supply in my Astrocity wasn't grounded at all and that there was a 75V voltage drift between the mains ground at the back of the cab and the Jamma harness ground. Shouldn't the AC100V in and the DC out to the JAMMA harness have a common ground to stop this voltage drift?
Title: Re: JPAC video quality issue, I think
Post by: keilmillerjr on April 22, 2019, 08:18:49 am
Had my electrician brother and his multimeter around over the weekend. He pointed out that the power supply in my Astrocity wasn't grounded at all and that there was a 75V voltage drift between the mains ground at the back of the cab and the Jamma harness ground. Shouldn't the AC100V in and the DC out to the JAMMA harness have a common ground to stop this voltage drift?

Low voltage dc can be isolated from ac. I see this *sometimes* with the cnc machines i work on.
Title: Re: JPAC video quality issue, I think
Post by: jimmyj1979 on April 29, 2019, 11:08:41 pm
hey mate i think i have the same issue as you

http://forum.arcadecontrols.com/index.php/topic,159278.0.html

Its almost like the JPAC output is too bright or intense and causing blooming or over exposure?

I'm getting used to it now after having two separate cabs with groovyarcade/JPAC's do this. I dont think we should be adjusting monitor pots to accomodate this, i thought it should be something to do with the JPAC.