How to Ground a VGA
Although the pros may take it in stride, wiring VGA connectors can be intimidating to those of us used to more simple 2- or 3-wire cables and ports. After all, 15 is a lot of pins...even if one or two of those pins go unused. However, after a quick peek into the arrangement of the pins, you'll see that it's not so overwhelming. And, with a little experience doing it, grounding VGA is very easy to understand.
Identifying the Pins
Always remember that D-sub pinouts start at the top -- the "wider" end of the D -- and go from right-to-left, not left-to-right.
Top row: Pin 1 is the Red video signal, 2 is Green and 3 is Blue. Pin 4 is almost always unused with modern VGA equipment, and pin 5 will be the ground (GND) for the Horizontal Sync signal.
Center row: the first three pins are your color signal "grounds" or returns. Pin 6 is often labeled RED_RTN, 7 is GREEN_RTN and 8 is BLUE_RTN. Pin 9 carries +5V DC in modern VGA cables, although older equipment may label this pin KEY instead of PWR. Finally, pin 10 (GND) is the common ground for the Vertical Sync and Data pins.
Bottom row: the first two pins are for data; pin 11 (ID0) is generally unused in modern VGA but pin 12 (ID1/SDA) is still commonly in use. Pin 13 is Horizontal Sync, and pin 14 is Vertical Sync. Finally, pin 15 (ID3/SCL) carries data clock signals.
Making the Connection
Cut your cable longer than you need. Too much cable is merely wasted space, but not enough can be a disaster for the project.
Strip the outside jacket of the cable carefully. A little too much force will cause damage to the more delicate wires inside -- in which case, you'll be very glad you left extra slack during Step One.
Strip each of the inside wires just enough for a good solder connection when inserted into the pins. About 6mm or 1/4 inch is a good estimate.
Slide the stripped wire into the corresponding pin of the VGA connector.
Apply the soldering iron tip and solder to the wire so that the solder flows smoothly to form a smooth and shiny connection with the VGA conductor. A dull (cold) solder surface may indicate a poor connection.
Repeat with the remaining wires and pins. If you're repairing one end of an attached cable (for example, one that is hardwired into a monitor), you're finished and can skip the next step.
Repeat the procedure with the other end of your VGA cable, making sure to match the color of each wire to the proper pin on the opposite end.
- A mounted clamp or hands-free holder can be extremely useful, as can a mounted magnifying glass and flashlight.
- Flux is also very helpful when soldering VGA -- become familiar with it if you're not already.
- Many people prefer to start in the middle of the connector and work outwards.
- It may sound silly, but make sure you have the correct gender before you begin soldering. Don't waste your time making a nice Male-to-Male VGA cable when what you really needed was Male-to-Female.
James Lee Phillips has been a writer since 1994, specializing in technology and intellectual property issues. He holds a Bachelor of Science in communications and philosophy from SUNY Fredonia.