JAMMA Cab, MAME & monitor issues. Help me, o great forum

[cooke]

Dudes,
I've got a generic JAMMA Double Dragon cab that
I've MAMEd with a J-Pac from Ultimarc. This thing totally RULES and works GREAT (after a TON of research and hard work).

I have, however, a slight
problem. After playing for about 30 minutes, the monitor begins to fade. It looks like it's going to fade out to black, but then it slowly comes back and
looks crisp and bright. Then, minutes later, the fading slowly begins again. Although it remains playable, this is highly annoying, as I'm sure you can
appreciate.

Naturally, I've tried placing the DD board back in the cab and it works great -- no fading at all, ever. This makes no sense to me and I
hope one of you might be able to suggest a solution. Since the problem only occurs when my computer is connected (through the J-Pac), I have to assume that
the issue lies not with the monitor, but with the J-Pac or computer.

Any ideas? Lemmie know.

Corey

[Diamond Dave]

Your running MAMe thats the problem, all the ghosts of the dead guys that developed those games are haunting you!!!! It's a Zen
thing.

[Weirdguy]

Your running MAMe thats the problem, all the
ghosts of the dead guys that developed those games are haunting you!!!! It's a Zen thing.

Dave, it's Karma, not Zen.

[Diamond Dave]

Ok, thats what I ment....too many Millers.........thanks

[machine.slave]

Your running MAMe thats the problem, all the
ghosts of the dead guys that developed those games are haunting you!!!! It's a Zen thing.

That's it, I'm reporting your avatar
to George Lucas!

[cooke]

Hmmmmm...... Is there some kind of cryptic assistance for my problem in there somewhere? Sheesh!

[menace]

I had the video amp on my jpac blow out once--causes the monitor to get 1volt on the colour lines as opposed to the usual 5 and it is very
dim--it could be yours is in the process of dying--email andy at ultimarc and ask him--if it is that, he will mail you a new chip to replace the old one.--
very great guy.

And ignore the mame haters--they're just jealous cause their basements/garages/actics are full but can still only play 20 games


(they secretly love mame but don't want to look uncool in front of the other mame haters)

[Ethous]

I Think that would be your best bet.
I have a jPac and the same
chip died I emailed them they had one sent to me in 3 days.
Was a nice responce

[leonk]

Also, what monitor/video card are you using? Some monitors can take the low voltage input, others
can't. (low voltage is what's put out by the PC video card, and a video amp on the JPAC amplifies it).

[cooke]

The monitor is an Electrohome G07 and the video card is an ATI Rage 128. But the mere fact that the monitor works in conjunction with the
computer (through the J-Pac) is indication that the monitor can handle the signal I'm sending it. If it couldn't handle the signal, the image would be
unusable altogether, it wouln't just fade in and out slowly. Right?

[menace]

Not entirely--you
have two aspects to your video--the signal frequency, in this case 15khz and the video amplitude (5volts for your typical arcade monitor) it sounds like you
have the frequency ok (the fact that you have a viewable image) but the amplitude is varying (the fact that it is going brighter and dimmer) So it could
either be your video card is outputting varied amps to the jpac (not sure if the jpca does a straight jump up on amps or if it varies depending on signal in)
or the jpac amp is flaky--try re-seating the small chip on the board--maybe you have an intermittent contact.

[cooke]

Thanks for the advice, Menace (and everybody). I'll take a look at the ol' J-pac chip tonight and see what I can see. I've also fired
off an e-mail to Andy at Ultimarc to see if he can shed some light on the subject.

Corey

[Edgedamage]

I had the video amp on my jpac blow out
once--causes the monitor to get 1volt on the colour lines as opposed to the usual 5 and it is very dim--it could be yours is in the process of dying--email
andy at ultimarc and ask him--if it is that, he will mail you a new chip to replace the old one.--very great guy.

And ignore the mame haters--they're
just jealous cause their basements/garages/actics are full but can still only play 20 games

(they secretly love mame but don't want to look
uncool in front of the other mame haters)

Mame haters!!!!!!!!!!!!!!!!!!!! PLEASE nothing can replace the feeling you get when
you fully restore a classic!! Untill those 20+ year old chips start going tits up. Then trying to get parts off some operator who charges $250 for
everything. Yes the classics look like crap on a pc monitor. Get mame running on a arcade monitor like I did and even mame haters take a second look.

[erdna77]

I wouldn't take a second look.

[Diamond Dave]

Nope me either??
I don't buy from operators, so I don't have to pay crazy prices??? If I need
chips I just order them for the electronics supplier??? I still think mame sucks.
But then again most of you don't live in your parents basements, so
you can't afford to drive a Corvette, and have 10+ fullsize games.