Installing a res switch for my Nanao MS8-26SU

[TravistyOJ]

I have a Virtua Fighter cabinet with a Nanao MS8-26SU 26" monitor.  This monitor is dual res, but in order to change it from med to low, you have to unplug a very hard to reach set of 4 wires, and replug it into another spot on the board. (As seen here http://www.jomac.net.au/photogallery/photo6739/MS8-26U.JPG) . 

To make this simpler I want to install a switch, since I have both med and low res games I want to play.  I think it wont be too hard, I am thinking if i get a dual pole 4 throw switch i can do it (like say a big knife switch), but I am no monitor expert.  Do I need to get a switch rated for high voltage, do these wires have a lot of current or no?  Any thoughts on this? Anyone done this before?

Also, anyone out there got a manual for this monitor?

Thanks

[Ken Layton]

Jomac in Australia is the Nanao expert. He might have schematics.

[TravistyOJ]

Also, you need to realize that this should NEVER be switched with the monitor on. It certainly is not designed for that, otherwise they'd have a switch already.  The problem is adding a switch only increases the likelyhood of you switching it while it's on.

Yeah, I actually plan on making a heavy duty switch cover for this, and I'm the only one that will use this cab.

Jomac in Australia is the Nanao expert. He might have schematics.

Cool, I will send him an email.


So what do you guys think? good idea? dumb idea? too dangerous?

[Jomac]

Thanks Ken

I use one of the monitors on my test rig and got sick of reaching in to change the plug all the time so I wired up 2  DPDT 12v relays to switch between resolutions.
Basically the 4 wires connect to the common pins on both relays , with no power applied to the relays they are in Normally Closed position which I have set up as 15K ( low ) the other 4 wires connect to the 25K ( High ) pins when power is supplied via a small switch .
Make sure you use diodes across the relays to prevent a spike back down the 12 volt supply when switching.


In case you're interested , if you do use switches instead of relays and try changing with power on , it will randomly kill the "HOT" not every time but it will happen .

This works perfectly ok when switched on using relays as they operate very fast , I don't recommend using just a switch unless you are only switching with power off.

I use 2 DPDT switches for inverting the picture , they need to be heavy duty 10amp type and mounted with a gap , I had tried this using a 4PDT switch first but there wasn't enough space between the terminals to insulate the Horizontal and Vertical wires.
 
The later model 29" Nanao's use a relay to change from low to high res , depending on the detected input .
all of the later WG's and others use relays and auto detect the res then switch while powered up.

I only have a hard copy of the schematic for this model and not really clear enough to scan , so if you need any specific info just let me know.


Please keep any question in the forum so other can benefit as well .
Regards,
Jomac

[TravistyOJ]

Awesome thanks for all the info!

[channel27]

Thanks Ken

I use one of the monitors on my test rig and got sick of reaching in to change the plug all the time so I wired up 2

[Jomac]

I am using 10 amp relays .
Not for the current rating so much but for larger contacts to prevent arcing if changing while switched on.

These are the exact relays I am using http://www.maplin.co.uk/Module.aspx?ModuleNo=37518&&source=14&doy=28m9

Jomac

[channel27]

Thanks Jomac, you're a star!