Jumping H Sync and V Sync on MS2931

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Londoncalling
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Jumping H Sync and V Sync on MS2931

Post by Londoncalling » August 18th, 2014, 12:41 am

Hello mates I have a net city with a Nanao MS2931 and it's locked me out of some resolutions. I'm in need of a tutorial or description on how exactly to jump hsync and vsync together to get it to work again. Hope someone can help! Cheers!

Londoncalling
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Re: Jumping H Sync and V Sync on MS2931

Post by Londoncalling » August 18th, 2014, 9:55 pm

Anyone? ? ? :(

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codecrank
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Re: Jumping H Sync and V Sync on MS2931

Post by codecrank » August 18th, 2014, 10:12 pm

hummmm, what could composite sync give you exactly ? not sure I understand the question :think:

Londoncalling
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Re: Jumping H Sync and V Sync on MS2931

Post by Londoncalling » August 19th, 2014, 4:48 am

There is a fix mentioned on the Wiki which says to jump HSync and VSync together and it should switch resolutions. But I'm not sure how to do it. :(

xga
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Re: Jumping H Sync and V Sync on MS2931

Post by xga » August 19th, 2014, 6:40 am

It was mentioned in this post http://forum.arcadeotaku.com/viewtopic. ... 20#p116156 by zorahk that Graig (giz10p) knows how to fix it.
I don't actually know how to permanently fix it but I know jumping hsync and vsync will allow you to force change the display mode or something like that. Craig (giz10p) is the one who actually knows how to fix it and the one I got all this information from.
Might be worth contacting giz10p and see what he says. I'm keen to know the process too, so post back if you find out.

Londoncalling
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Re: Jumping H Sync and V Sync on MS2931

Post by Londoncalling » August 19th, 2014, 2:47 pm

Ok mate I'll shoot him an email and report back with the response. Cheers!

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HyperBolt
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Re: Jumping H Sync and V Sync on MS2931

Post by HyperBolt » August 22nd, 2014, 4:07 am

If anyone has a neogeo forum account, they should look up ken from the game room's account.
He's one of the suppliers of candy cabs in the US.
I don't know the exact account name nor do I have a neo geo account.
He mentioned in one of his posts about a component going bad that would lock you out of resolutions.

He also mentioned that using a step down converter would prevent it.
At least for those in the USA, since I imagine everyone else already uses a step down converter.

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Tochir0
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Re: Jumping H Sync and V Sync on MS2931

Post by Tochir0 » August 19th, 2019, 10:15 pm

(Hope no one minds the necro)

Like the OP, I want to see if anyone could give me some pointers on jumping the h sync and v sync on an MS2931. My new blast only works with 31 khz but when I use my CPS2 the image is scrambled. I suspect a faulty auto sync switching function, which is why I'm planning on 'Jumping H sync and Vsync together' as mentioned in the wiki.

I'm not sure if I should run a wire from the h sync pin (#4) in the AMP UP connector socket of the monitor to the v sync pin (#15). Or perhaps I should disassemble the connector and combine the two sync lines into one and put that into the h sync pin (#4).

I'd be interested to hear from anyone who's experienced (and hopefully solved) a similar issue. Thanks for looking!

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grantspain
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Re: Jumping H Sync and V Sync on MS2931

Post by grantspain » August 19th, 2019, 10:26 pm

you would just put a short from h to v sync, not sure why that would work though
more likely a factory reset would help

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Tochir0
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Re: Jumping H Sync and V Sync on MS2931

Post by Tochir0 » August 19th, 2019, 11:05 pm

Thanks for post grantspain. I'll try the factory reset first then the short and will report the results,

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