Best solution for forcing monitor detection?

[yatzr]

I've got a setup with a win7 machine with an ati hd4550, a jpac, and an arcade monitor.  If the hd4550 is hooked up to the jpac when the computer boots up, it'll think there's no monitor connected to it, so it won't output any video until I restart the computer.  My solution so far has been to connect 75ohm resistors from the r/g/b lines to ground to trick the hd4550 into thinking there's a monitor during bootup.  I did this by soldering resistors to a switch on the underside of the jpac so I can switch the resistors off after bootup.  This works okay, but if I leave the resistors switched on, the video is much dimmer than I'd like.  It's also a hassle to open my cab to switch them on for bootup, and then off to get proper brightness.

I'm wondering if anybody has a better solution for this.

[mgb]

Just a quick, off the top of my head thought but what if  you simply replaced your switch with a timer relay.

http://www.altronix.com/products/product.php?name=6062

With this relay you can terminate your resistors from the rgb lines to the relays common and then a line from the relays
N.O. to ground.
The relay can then be powered and triggered off the PSUs 12 volt line to just close the contact for a long enough time for bootup and then the relay goes back off and the grounds lifted. 

[yatzr]

Just a quick, off the top of my head thought but what if  you simply replaced your switch with a timer relay.

http://www.altronix.com/products/product.php?name=6062

With this relay you can terminate your resistors from the rgb lines to the relays common and then a line from the relays
N.O. to ground.
The relay can then be powered and triggered off the PSUs 12 volt line to just close the contact for a long enough time for bootup and then the relay goes back off and the grounds lifted.

I like it!  However, the switch I currently have is a triple pull, and I have each rgb line going to the switch, then to a resistor to ground.  So when it's off, the rgb lines are just like normal.  With just one of those relays, when it's off, I'd still have the rgb lines in a three resistor Y formation.  It's been a long time since I took my EE classes, so I have no idea what that'll do to the lines, but I'm assuming it would affect them in some way.  Maybe if I can find some relays cheap enough, I could just get 3.

[mgb]

yes, sorry, you're right. you wouldn't want the resistors from each line being left tied together but you can add another means to separate them.
you can add in a relay with 3 or more poles controlled off the timer relay. so then the resistors are kept separate.

I know it seems a little like one of those mouse traps from old Tom & Jerry cartoons but it would work

[yatzr]

Ah, yeah I think that solution would be just fine.  I was sitting here trying to find a timer relay with 3 poles, didn't think about using a regular one controlled by the timer.  Thanks!

[mgb]

Yeah, I'm not aware of a 3 or pole timer relay.
  If you do get the timer relay, the altronix one is good.
We use them in commercial and industrial fire alarms and other systems and I've never had one fail me.

http://www.amazon.com/gp/aw/d/B003Y021VY?pc_redir=1411904032&robot_redir=1

[yatzr]

I ordered that guy's little brother, the 6030, cause I found it for $11.  I also got some little dpdt relays from digikey cause that was the cheapest way to get 3 poles.  If I get this all working, I'll put together a detailed post with pictures.  I'm pretty excited about it.  Big thanks for the idea!

[mgb]

Oh yeah, that makes sense. I didn't even know anout the 6030 because I'm usually using them with 24 volts.
Cool deal.
Hope it all works well.

[yatzr]

Got this all rigged up.  It works great!
http://forum.arcadecontrols.com/index.php/topic,141999.0.html