Each pin in a VGA connector has a specific role in carrying RGB color, horizontal, and vertical sync analog signals from the VGA output port on a computer to a VGA-enabled monitor.
Below is an overview of the primary pins and their functions.
Essential Pins in VGA Connector
Pin 1: Red analog video signal
Pin 2: Green analog video signal
Pin 3: Blue analog video signal
Pin 13: Horizontal Sync information
Pin 14: Vertical Sync information
Pins 6-8: RGB ground signals for preventing signal interference
Pin 5: Horizontal sync ground
Pin 10: Vertical sync ground
The red, green, and blue analog video signals are encoded from the VGA output port on the computer and transmitted to the VGA-enabled monitor.
The monitor then decodes these analog video signals as pixel points on the screen.
Horizontal Sync synchronizes the display of each line of pixels, while Vertical Sync synchronizes the display of each frame of pixels.
Unused Pins in VGA Connector
Some pins on a VGA connector are no longer used, namely pins 4, 9, 11, 12, and 15.
Pins 4, 11, 12, and 15 were once used to identify the monitor type when the VESA Display Data Channel (DDC) standard was applicable.
However, the Enhanced Display Data Channel (E-DDC) standard replaced the DDC standard in 1999, eliminating the monitor type identification function.
As a result, pins 4, 11, 12, and 15 are now reserved and no longer used.
Pin 9 was initially used for keying functions to prevent incorrect plugging of the VGA connector into the VGA port.
Later, its function was switched to a +5 V DC power supply, which is not necessary for VGA’s video transmission purpose. Hence, Pin 9 is also not used anymore.
Will a VGA Cable/Port Work with a Missing Pin?
Yes, not all 15 pins are required for a VGA connection. If your VGA cable/port is missing a pin, it is still possible for the cable to work. However, whether the cable works or not depends on which pin is missing.
As discussed earlier, 5 VGA pins have become redundant and are not required for a stable display connection. These pins are also called reserved pins.
Therefore, if you are missing any of the reserved pins on your VGA cable, including 4, 9, 11, 12, or 15, your cable can still function properly without them.
If your VGA cable is missing any other pins apart from the reserved pins, you will have to get your cable fixed or replace it with a new one.
How Do I Fix a Broken VGA Pin?
If you have a broken VGA pin, you can follow the tutorial shared above to fix it.
There are various methods of fixing broken VGA pins. Here are the most common ones:
1. Use Pliers to Fix a Crooked VGA Pin
How to Fix a VGA Cable Connector with a Bent Pin
It is common for VGA pins to get bent or crooked while you try to plug them in. If you notice a bent VGA pin, you can easily fix it at home.
It would be best if you had a good old pair of sturdy pliers and used them to straighten and unbend a VGA pin.
2. Solder the Pin
If you are experienced in repairing electrical devices or metal components, then you can try to use a soldering iron to solder the broken pin back into place.
However, you have to be very careful while doing so to avoid damaging any nearby pins.
Tech experts recommend going to a computer repair shop for this purpose and letting professional experts take care of the job.
3. Replace the Cable
Sometimes, the cost of repairing a small component is higher than the price of the project itself.
Nowadays, a VGA cable typically has 15 pins. However, did you know that there is also a 14-pin VGA cable version?
Distinguishing a 14-pin VGA cable from a 15-pin VGA cable lies primarily in the absence of pin 9.
Historically, pin 9 was eliminated from VGA cables due to its obsolescence in modern computer monitors, rendering it unnecessary for default VGA applications.
Nevertheless, pin 9 has recently been revised to supply power to the EDID EEPROM chip on some monitors.
The Role of Pin 9 in VGA Cables
In the past, pin 9 was required by most plasma TVs because of its role in providing vital information about the monitor’s available resolution back to the computer graphics card.
This pin transmits a 5-volt signal to the DDC (display data channel) in the computer graphics card.
However, newer computer monitors such as LCDs appear to function adequately without this pin.
Bonuses
1. How To Tell if My VGA Cable Is Working or Not?
It is important to restart your devices to confirm whether your VGA cable is working fine or not.
Make sure that you first unplug all your devices that your VGA connects to. This will include your computer and monitor.
Once all the devices are unplugged, then remove the VGA cables from their connection.
Now all you need to do is wait for a minute or two before reconnecting the VGA cable to your computer and monitor.
After reconnecting the VGA cable, plug in your devices and check whether the VGA cable is working or not.
2. My VGA Cable Has All 15 Pins. Why Is My VGA Port Still Not Working?
If you do not have any pins missing from your VGA cable, but your VGA port is not working, there could be other reasons.
This usually happens because of outdated or malfunctioned graphics card drivers. Therefore, make sure that your graphics card driver is up to date and in proper working condition for a stable VGA connection.
The Bottom Line
To summarize, the final answer to ‘Will a VGA cable or port work with a missing pin?’ is ‘Yes.’ Your VGA cable/port will still work with a missing pin as long as it is a reserved pin.
Hai Huynh, an Electrical & Electronics Engineering graduate from Ho Chi Minh City University of Technology, is a passionate technical editor. He discovered his love for technology when he started playing Pokemon on a Gameboy as a child. Now, he writes and edits technical articles, focusing on smart TVs and streaming devices, to help readers solve problems.
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