Midway PCB are too dark!!!!!

[kungfoune]

Hello,

I'va a problem with some board. I explain:

I have an egret3 toshiba and I love midway boards. So I bought Mortal Kombat 1, Mortal Kombat 2 and NBA JAM (and look for UMK3 too!). But when I wanted to use them, the same problem the three: a very dark video...





I test the same boards on a NAC and no problems! In order to find a solution, I buy from Franc B (thanks a lot buddy) a negatron with jamma connector... but the problems are the same and I have the same sound I've had before (like the negatron does nothing...).

What's the problem with my cab??? Does anyone with the same cab had the same problems???

Thanks for your quick response!

[Asure]

On your monitor adjustment board, check if there is a high/low switch yet?

[thomj]

Try shorting video ground and common ground with a bit of wire.

Also, have you metered the -5 to check the negatron is working?

[kungfoune]

On your monitor adjustment board, check if there is a high/low switch yet?

on the monitor? I don't understand when I should see!

[kungfoune]

Try shorting video ground and common ground with a bit of wire.

Also, have you metered the -5 to check the negatron is working?

I check -5v out of the connector with negatron and it works... How can I make the connection that offers you?

[thomj]

http://forum.arcadeotaku.com/viewtopic. ... 793#p44765"

[kungfoune]

ok, I will check it tonight! I will buy a wire and test to connect on jamma loom

[FrancoB]

Unfortunately that won't solve the problem. We checked that your video GND is linked to GND last night with your multimeter in IRC.

[kungfoune]

hi buddy! this is what we check yesterday? arf.... I think these pcb need more power! If I increase +5v or 12v, can I break pcb?

[Asure]

Need better information before we can help you.

- What is your monitor (chassis) type?
- Did you check if you have a video voltage / impedance switch for low/high video?

Many monitors have low/high switches on the panel where you adjust the picture, which is usually under your control panel for easy access.
The reason is VGA/Jamma uses different voltage RGB signals. If yours is set for high signal, normal arcade boards like this will look like they have too low brightness.
So post some more info on your monitor, we can go from there.

[Shou]

Do you have any Irem PCBs? Irem and Midway PCBs have dark images.

[kungfoune]

Need better information before we can help you.

- What is your monitor (chassis) type?
- Did you check if you have a video voltage / impedance switch for low/high video?

Many monitors have low/high switches on the panel where you adjust the picture, which is usually under your control panel for easy access.
The reason is VGA/Jamma uses different voltage RGB signals. If yours is set for high signal, normal arcade boards like this will look like they have too low brightness.
So post some more info on your monitor, we can go from there.

I have an Egret3 cab with toshiba (monitor and platine). I don't know if I have impedance switch or video voltage on it... It's an osd control panel like this:

http://i37.servimg.com/u/f37/16/81/31/01/cimg4313.jpg"

[Asure]

Ok i looked around and saw these monitors and the adjustment osd board, even the secret menu for this type.
But there is nothing for the voltage levels. You can adjust brightness from the menu, so that's a start.
There is r/g/b gain levels that can also be adjusted in the hidden menu. But i would suggest not to mess with that right now.

If the problem is only with some older PCB, you can use some sort of rgb amp to get the video up to normal level.
Like this one http://www.ultimarc.com/vidamp.html".
Then, wire it in between the jamma and your monitor. Then you can play Jamma pcb's with this problem by switching some cables. I do not have any other suggestions at this point, sorry

[SuperPang]

That's a great monitor and should work with everything. You have tried contrast and brightness right?

[kungfoune]

That's a great monitor and should work with everything. You have tried contrast and brightness right?

yes it's a great monitor but this the second problem I have with it!! The first is with soulcalibur PCB that have video problem with colors. And for now, nobody knows how to repair this problem... I tried 2 different PCB of Soulcalibur and thi is the same problem with both! Another member in neo arcadia forum created a topic for the same problem with a CPS3 board but no response at all...





For midway pcb problem (for me more important than soulcalibur), I tried to increase brightness on the osd menu but it's not very good in quality... too poor in color... not good at all!!

[kungfoune]

Ok i looked around and saw these monitors and the adjustment osd board, even the secret menu for this type.
But there is nothing for the voltage levels. You can adjust brightness from the menu, so that's a start.
There is r/g/b gain levels that can also be adjusted in the hidden menu. But i would suggest not to mess with that right now.

If the problem is only with some older PCB, you can use some sort of rgb amp to get the video up to normal level.
Like this one http://www.ultimarc.com/vidamp.html".
Then, wire it in between the jamma and your monitor. Then you can play Jamma pcb's with this problem by switching some cables. I do not have any other suggestions at this point, sorry

but your solution is for vga cable...!

[Rossyra]

I appreciate it has already been ruled out, but those look a lot like video ground issues to me. I would check the entire video ground line from the monitor all the way to the edge for continuity.

When RGB lines are being driven too high, it can look like the palette has shifted on screen.

[kamex]

That is weird with the SC board... I actually have a similar problem with a different game though much less severe. No clue what causes it.

[kungfoune]

nobody can help me? I don't want to sell these PCB!!