connect PC to arcade monitor?

[BLASTEROO]

Hi all!

I'm converting an old generic cabinet to mame and I'm thinking in using the existing arcade monitor.
Is it possible to connect the output of the vga card directly to the arcade monitor (Hantarex)?
I'm planning to use soft 15 kHz.

Cheers!

[BLASTEROO]

I've been testing the arcade monitor.

It takes a long time to have a picture on the screen after you switch the cabinet on.
The monitor starts working immediately but the picture only appears several seconds later and it has a green dominance.

Is this a bad sign?

[dosmame]

yes it's possible to get a picture with a direct connection and soft15khz, but, the VGA output voltage will be so low that the display will probably be very dim

what most ppl do is use a video amplifier like a j-pac to amplify the VGA signal to a level that the arcade monitor can use effectively

see my block diagram at the bottom of my page

http://dosmame.mameworld.info/index.php/x64_MAME_Cabinet

[Gray_Area]

Hey, blast, did you happen to know that there's a......wait for it......wait for it.....

http://wiki.arcadecontrols.com/

[DillonFoulds]

Gray_Area is correct. This is all covered very well in the wiki.

As for the VGA voltage being low, disregard that. The video output will be fine. If you find it dim, turn up the brightness. If in the very odd chance that it's still too dim, even after you've got it as bright as it can go, Andy at Ultimarc sells a video amplifier circuit.

Pull the RGB signals off the vga (refer to http://pinouts.ru/Video/VGA15_pinout.shtml), you can pick any ground on the vga cable you'd like to use for the ground signal to the monitor. For Sync you'll need to determine if your monitor prefers Horizontal, Vertical, or composite. Composite is a combination of horizontal and vertical on the same line. No more no less.

Install your video card drivers, and run Soft15KHz. Refer to the soft15KHz for assistance.

[BLASTEROO]

Thanks for the input guys.

You've been a lot of help! 

Any thoughts on the monitor's slow response on power on and green dominance image?

[newmanfamilyvlogs]

Green dominance is probably an issue with the Green drive pot. It should be on the neckboard. You can adjust the drive and bias for RGB there.

As for the slow to come up, I'll assume that's something like a power supply issue, but I really don't know.

[DillonFoulds]

Seconded on the green issue, sometimes it's easiest to set all colors the same, and adjust from there. First try just turning down the green a bit though.

As for slow boot, mine takes 10-15 seconds to fire up. It's not too bad. I recall my old CRT tv taking a similar amount to warm up. If you find it's really extensive, you can look into doing a cap kit?

[BLASTEROO]

I have found the Hantarex MTC9000 service manual on the web
and I can see exactly what you mean by adjusting the Green drive on the neck circuit. 

I'll tweak the green channel a bit and see what happens.

Here is the link for the Hantarex MTC9000 service manual, if anyone needs it:

http://arcarc.xmission.com/PDF_Monitors/Hantarex%20MTC9000%2014in%2016in%2020in%20Manual.pdf

[BLASTEROO]

Turned down the green drive and...  everything is looking a lot better! 

Focus seems to be a little off, even in the best possible adjustment... any pointers to get a crispy image?
Comparing the Hantarex image with my Sony scart TV that I have installed in another cab, the Sony wins by a long shot.

The slow boot issue seems to have disappeared, as the Hantarex is now firing up real quick, taking no more than 10 secs to display the image.
Maybe because of it being stored in a warehouse for a long time, the circuit went totally out of juice (capacitors and such)? 

[DillonFoulds]

When you say out of focus, what's your source?

If it's a pc running mame, make sure you configure your mame following andy's guide:

Code: [Select]

#
# VIDEO OPTIONS
#
video ddraw
numscreens 1
window 0
maximize 1
keepaspect 1
prescale 1
effect none
pause_brightness 0.65
waitvsync 0
syncrefresh 0
#
# DIRECTDRAW-SPECIFIC OPTIONS
#
hwstretch 0
#
# FULL SCREEN OPTIONS
#
triplebuffer 0
switchres 1


[BLASTEROO]

Dillon,

Thanks for the input 

In this case it's a jamma cabinet and the monitor is an Hantarex.
You can see the focus problem clearly if you pay attention to the games fonts, that's where it's more evident.
Also the shapes and colors are blurry (not massively but you can tell that the image lacks detail).

Already tried several jamma games (including neo-geo) and the result is the same.

If you play for an hour or two, your eyes get real tired.
I tried switching to a "new" flyback but the problem remains.

When comparing the Hantarex in the best possible focus adjustment (via flyback pot) to my converted scart Sony TV (installed in another cab, running Mame) that's when it becomes pretty much evident.

Could this be an aging tube problem? The guy who sold me the cab said that an aging tube manifests it self in different ways such as color dullness and unbalance... not focus problems.

According to him, the current (almost focused) image is the best the Hantarex can offer.



 

[BLASTEROO]

Hi guys!

Any ideas on the Hantarex out of focus problem?
Is there a common solution for this, like recaping or something similar?
I've been hitting the old games a lot lately and after 2 hours of blastorama my eyes almost colapsed of pain.
Should I go for a new monitor or there is still hope for this seasoned Hantarex mtc9000?

Any input welcome!

[BobA]

Depends on your specific monitor but here is some general info.

First, we’ll start off by locating the focus and brightness controls on the flyback. Locate the flyback on your monitor chassis. It is usually a big black cylinder attached to the anode (located underneath the suction cup) by a red wire. On the flyback there should be two knobs. The top one is usually the focus and the bottom one the brightness.

[BLASTEROO]

Hi BobA,

thanks a lot for the input!

I've already tried that.
The top pot on the flyback is what controls the focus and I've tweaked it as much as I can.

The result is an almost focused image.
By looking at it you sense that it's almost there, but not quite there on the spot...

Already tried a different chassis (and flyback) but the problem persists.

[BobA]

Sounds like cap kit time.

[DillonFoulds]

He said he already tried a different chassis, ergo different caps, no?

Would a rejuvenator perhaps help more in this case? IDK for sure, but just a thought, especially if it's a tube issue.

[mgb]

If your going by the text in games. make sure your contrast (if there is one on that monitor) is adjusted correctly. I've had that alot where the contrast is up too much and the text will ghost a bit.

[BLASTEROO]

OK guys,

I just got my hands on 2 second hand Hantarex mtc9000 chassis.

This should clear out if the problem is chassis or tube related.

Just need a little bit of time to do this properly and by the book. I'm not much of a technician... but I think I will manage.

I'll report back as soon as I get this done.

Thanks for the support! 

EDIT: Can I have your comments on this related thread?

http://forum.arcadecontrols.com/index.php?topic=107910.0

 

[mgb]

As far as the text looking outta wack. I had a Donkey Kong (sanyo ez) that the text looked like garbage on. I guess some could say it looked like focus but it was actually the convergance rings that needed adjustment.
I don't advise messing with these adjustment rings though unless you enjoy headaches, but one sign of that can be multiple colors around text.

[BLASTEROO]

mgb,

You have just hit my current "what if" question right on the bull's eye!

Man, yesterday while consulting on-line literature about chassis and tube compatibility, cap kits installation and such,
that same possibility struck me.

What if the R G B convergence rings play a role on this out of focus issue?

I will start by swapping the chassis. If that doesn't change anything in the focus problem I will most certainly try to adjust the convergence rings.

If I go in that direction, what is the best way to adjust it? A color bar or a black and white grid?

The focus problem is a real pain to my eyes and I doubt I will leave it this way.

My buddies and I, we're planning to celebrate during the new year's night with an arcade bonanza
and I was hoping to have this ready for the occasion...   

Thanks a lot for the input! 

[newmanfamilyvlogs]

Convergence rings are a special kind of hell. Even looking at them with the intention of touching them can screw them up.

I'm too much of a tinkerer and though "You know, the convergence on this monitor isn't great, I bet I can fix it!"

that was three months ago, and it's still only 'close'

[mgb]

I have seen sometimes where you can possibly line up the old glue on the rings and maybe get it right on. But I've only actually adjusted the rings once. It was on a DK. I had just capped it, replaced a broken pot for the B+ adjustment (after I first broke it) and then I adjusted the B+. My customer and I noticed that while it looked pretty good, the text on the screen looked almost like a triple image with 3 different colors, the white text with an upper left red and a lower right blue. Bassically I tweaked the rings a slight bit while the customer told me if it was getting better or worse. It was not fun man, but it ended up looking great with the text as crisp as possible.
I know there are proper ways to adjust the rings, but I just tweaked them to clear up the issue I saw at hand.
I wish I could give some better advice on this but I will say be careful if you do that. Make sure to take good care to know where your starting off at so you don't make matters worse. Try to get someone to watch the monitor for you while you make very small adjustments and constantly stop and look at the screen yourself rather than just trusting the spotter.
good luck
have you tried messing with the contrast first?

[BLASTEROO]

mgb and cotmm68030,

I will mark the current convergence rings position with a white correction pen, so If the situation gets ugly I can reverse to the initial state.
Just to be sure I'll mess with the contrast pot again, before embarking on the chassis swap adventure.

Man, it really sucks wanting to play some games and not being able to, because of this focus debacle.

Stay tuned! 

[BLASTEROO]

Ok guys,

I finally tested the tube with the 2 "new" Hantarex chassis but the focus problem remained.

After messing with the contrast, brightness and focus one final time, with no results,
I removed the suspicious 19'' tube out of the equation and tested the 2 chassis on a 25'' tube.

The focus problem is gone  .

Result, a much more sharper image and better color response, but some vertical size issues:



The pic above shows the maximum vertical size I can get with this 25'' Nokia tube, which I was hoping to use.

Tried a friend's videocolor 25'' tube with the same chassis and the image adjusts nicely to the screen:



I'm puzzled with this situation.

Any idea why is this happening? Please share your thoughts.

[newmanfamilyvlogs]

A chassis for a 19" won't be able to drive a 25" tube to fill the entire screen. In the second pic, it's upside down because the vertical yoke coil is plugged in backwards.

[BLASTEROO]

cotmm68030,

That makes sense, but what puzzles me is having the nokia 25'' tube not filling the screen and the videocolor 25'' tube filling the screen perfectly,
using the same chassis for both tubes.

Both screens are 25''. Shouldn't the results be the same, geometrically speaking?

When I measured the yoke I remember that the nokia had a much lower impedance than the videocolor tube,
but I need to check that again to be sure.

Could this be a factor to consider?

[mgb]

Yeah,
the impedance of the yoke will definately be a factor

[BLASTEROO]

ok,

I have measured the yokes:

nokia 25'' tube:

V: 6 ohms
H: 2 ohms

videocolor 25'' tube:

V: 10 ohms
H: 2 ohms

Would a 25'' to 29'' chassis solve this issue?
Currently I'm using a specific 25'' chassis.

Your input is highly appreciated