Saturday, September 24, 2011

Make your own EVC to VGA adapter

Here is a tutorial I created several years ago just for the heck of it. I happened to need the info myself and figured I would share what I found. I had it on a different site, but then shut down that site, so now I'll just post this info here in case one or two people actually happen to need this info. I know it's not going to be useful to very many people. I spent a lot of time on it so I may as well make it available. 

I don't know if I mention it in this tutorial since I haven't reread it, but the HP workstation I had was configured for a higher than mainstream frequency monitor. So not your typical 60 Hz or whatever. There is a way to set it for a regular monitor, but it's pretty hard to do without a monitor that works with it in the first place (which I didn't have). I got my monitor to work once but then had to restart and lost the settings and never got it working again. Maybe someone else will know more about how to do this. So I didn't get much use out of my cable. I just got fed up with it and gave the workstation and my home built adapter to my brother.

Oct. 2007

Make your own EVC to VGA adapter.

click image for full size
I recently purchased an HP Visualize C180 Workstation at a second hand store for $10. At first glance the video out looked like DVI. But come to find out after trying to plug in a standard DVI/VGA adapter, the DVI plug is much smaller. After some searching I found out that it is in fact an EVC (enhanced video connector) plug. (dvi/evc comparison)
EVC is a pretty cool concept that never took off. EVC combines Video, Audio, Parallel, USB, and Firewire all into one socket. It was meant to reduce the clutter of cables. You could have a monitor with a single cable connected to the computer and all the IO ports you need right on the monitor.  (evc concept)
I didn't have to search much to find out that EVC to VGA adapters aren't cheap, at least $40. Well I didn't want to spend $40 more on a $10 computer. I found an EVC to dual VGA splitter on ebay for around $9 after shipping.

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This cable is not compatible with the standard EVC pinouts, but that can be changed. (evc pinouts) (vga pinouts) I was unable to find out exactly what this splitter is actually for, maybe for a special video card with dual VGA out, but that information is irrelevant to my needs. The part number is 05E911 made by Molex and they can be readily found on ebay. HINT: most people selling them on ebay think they are DVI to VGA adapters and they are advertised as such. The best way to tell is that EVC has 3 rows of 10 pins and not 3 rows of 8 like DVI. (dvi)

click image for full size

click image for full size

Here is a table that shows which pins are wired together. Each plug has it's own column and the rows show which pins are connected. The "correct VGA" column shows the correct way to connect a VGA plug to the EVC plug. (evc/vga adapter)
EVCVGA 1 (blue)VGA 2 (black)Correct VGA (wire color)
410 (brown)
513 (white)
614 (red)
2575 (orange)
2612 (green)
271015 (black)
28129 (yellow)
C111 (red shielded wire, center wire)
C222 (green shielded wire, center wire)
C4133 (blue shielded wire, center wire)
C56,7,8,106,7,8 (shielding to shielded wires)
Required items to get started:
    - Molex part# 05E911 EVC to dual VGA adapter.
    - Knife
    - Pliers
    - Soldering Iron
    - Solder
All the work will be done on the back of the EVC plug, so we need to open it up. Begin by working a thin object (knife) in between the plastic and the metal on the front of the EVC plug as show in the picture.
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Remember what you learned in Boy Scouts, don't go cutting toward yourself or your neighbor for that matter. Safety First!
The plastic housing is glued on each side to a metal housing which is soldered to the back of the EVC plug. You need to work the knife in between and side to side to break the bond. I found that it makes it easier if you twist the blade and pry the plastic away from the metal rather than cutting it.
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After all the glued surfaces are separated, hold onto the plastic housing with one hand and use the other hand and push the cord into the housing and the EVC plug and metal housing should pop out as shown below.
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Take a pair of pliers and squeeze the crimped end of the metal housing as shown below. We are trying to loosen the crimp on the wires so they can be slid through.
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The metal housing is soldered with two small beads of solder, one on each side. I found that it would be easier to cut the solder rather than melt it. Solder wick might work as well but I didn't have any at the time.
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Use a pair of pliers and grab onto the flange on each side and twist gently to break the remaining solder. Use this same method to work the EVC plug out of the metal housing. Make sure to feed the cord through the crimped end of the metal housing as you work the EVC plug out the other end.
click image for full size
Below are images of both sides of the EVC plug just after the metal housing is removed. As shown in the table above, this wiring scheme is completely useless to us. Desolder all the wires from the back of the EVC plug. Technically you could leave the 2 good solder points connected, but I didn't because I like how the "VGA 2" wires have shrink tubing on the shielding whereas the "VGA 1" wires were a mess. The finished product will only have one VGA out so you will have to choose which one to use and put the leftover in your parts bin for future use, or give it to a geek friend for Christmas. :-)
click image for full size
click image for full size
After you have removed all the wires and decided which VGA you are going to use, turn right back around and solder the VGA of choice back onto the EVC plug the correct way and there you have it. Below are some pictures of the way it should look when you are finished. Make sure you check and double check your work.
click image for full size
click image for full size
Now just reassemble in reverse order. Make sure to resolder the metal housing to the EVC plug and use a little glue between the metal housing and the plastic housing. That way it wont pull apart when you are unplugging it from your computer. Also recrimp the back of the metal housing around the cord to provide strain relief.  I guess before you solder, glue, and crimp it back together, you might want to test it out and see if it works. Otherwise it could be fun taking it back apart to fix it if it doesn't work.
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The picture above is of the finished product. Now if when you follow these instructions on this page and anything gets damaged, remember I'm not responsible. If your $50,000 Workstation sits before you in flames, take heart. Get out your video camera and record the fun, then post it on youtube for us all to enjoy!

1 comment:

  1. Interesting, it looks like the grid lines for the pin-outs spreadsheet don't show up in the Chrome browser, but they do in IE and Firefox. I don't know why that is.