Monitor trouble shooting

Hey, I have a Darkstalkers cab, and when I hook up my 4-slot mvs. The picture on the monitor is flip upside down. Is there a "hold" dial I can twist so that the picture looks correct without having to turn the monitor upside down?

First thing is check to see if the Darkstalkers PCB has a DIP for screen flip. If so, mount your monitor upside down and throw the DIP on the Darkstalkers board.

Neo Geo boards do not support screen flip.

It's not the DS, I have sold it, but I do remember it being in the options. But the monitor has a case (flat level platform that it rests on) When it is laying flat like it would in the cabinet, and I hook the mvs up to it, the image is upside down. To solve this I have built/rigged for the monitor to physically be upside down, so the image would be corrected. I want the monitor to be in the original position with the correct screen image.

You could simply reverse the deflection yoke vertical and horizontal scans. A lot easier than inverting the whole monitor.
IF YOU DO NOT UNDERSTAND THE SAFETY ISSUES, DO NOT ATTEMPT THIS.

Follow the leads from the deflection yoke back to the monitor PCB. There will be 4 wires, colour coding is usually (but not always)

Red/Blue- Horizontal scan
Yellow/Green- Vertical scan

Pull this scan coil plug on the monitor board, you will see it has a keyway (a gap inbetween the red and blue lead (horizontal scan)THE GAP IS ALWAYS INBETWEEN THE HOR SCAN LEADS. Cut the plug in half as shown below.

--------------V cut plug here-------
XXXX---XXXX---XXXX---------XXXX
YEL-----GRN----BLUE---GAP---RED

Then reverse each half plug as follows.

XXXX---XXXX....XXXX---------XXXX
GRN----YEL.......RED----GAP---BLUE

You cannot get it wrong because of the keyway, it will be impossible to get the vert crossed with the horizontal (without using a lot of force)

Alternatively you could always reverse the scan on the yoke itself but this requires some solder work. Or invert just the CRT.

Just for reference incase you get mixed up
Vertical coils approx 12 ohms
Horizontal coils 1.5 ohms

I will post a piccy if anyone is interested.

<small>[ March 26, 2003, 06:58 PM: Message edited by: ttooddddyy ]</small>

Before and after

This method allows easy switch back to the original orientation.

<small>[ March 27, 2003, 04:25 AM: Message edited by: ttooddddyy ]</small>

Toddy, remind me to put you in charge of creating a monitor section on hardMVS.

I don't know why I have not done it yet...

Todd- thanks for the advise and pix, I will try it tonight and let you know. Briggs great attempt and thanx anyways.

You will need a very sharp knife, I used a sharp pen knife for this, a Stanley would be better. Cut as straight as possible not to expose the conductor sockets, its no problem if they are exposes as long as they are held securely in the plug. I find it helps to cut half through from one side then turn it around and cut through the other way.
You will find a dummy pin inbetween the H scan connections, remove this, its just a blank. Look on the underside of the board and you will see it doesnt connect to anything.
Good luck.

How did you go with the scan reversal neodogg, did it all go up in smoke