4 Port Dual DVI USB KVM Switch with Audio

Monitors may begin flickering when they receive a signal of insufficient quality. There are a few potential fixes available that will help to improve the signal quality in order to eliminate flickering:

• Replace Video Cables with high-quality Video Cables (e.g. upgrade DisplayPort 1.2 Cables to DisplayPort 1.4 Cables).
• Use shorter Video Cables to reduce signal attenuation.
• When possible, remove Video Adapters to use native Video Connection Types (e.g. go from VGA to VGA, or DisplayPort to DisplayPort)
• For DisplayPort Monitors, try changing the DisplayPort Version on the Monitor. For information on how to change your Monitor Settings refer to the Manual from the Monitor Manufacturer.
• Update the Drivers for the Computer’s GPU to the latest available from the Monitor Manufacturer.

In order for your mouse to move properly between your monitors you must rearrange your monitors in Windows to match the physical location of your monitors on your desk. To do so, complete the following based on your operating system:

Windows 10 and Windows  8

1. On your keyboard, press the Windows key + X and select Control Panel.
2. Click Appearance and Personalization, then click Display.
3. Click the Resolution or Adjust Resolution option from the left column, which will display your monitors as numbered icons.
4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
5. Click and drag the monitor icons to best match your physical setup.
6. Click OK to apply the changes and close the window.

Windows 7 and Windows Vista

1. Click the Start button and select Control Panel.
2. Click Appearance and Personalization, then click Display.
3. Click the Resolution or Adjust Resolution option from the left column, which will display your monitors as numbered icons.
4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
5. Click and drag the monitor icons to best match your physical setup.
6. Click OK to apply the changes and close the window.

Windows XP

1. Click the Start button and select Control Panel.
2. Double-click Display.
3. Click the Settings tab, which will display your monitors as numbered icons.
4. Click Identify to display the numbers on each connected monitor, showing how the operating system has assigned their positions.
5. Click and drag the monitor icons to best match your physical setup.
6. Click OK to apply the changes and close the window.

To mirror the image from your primary monitor instead of extending your desktop, refer to the following FAQ: http://www.startech.com/faq/Windows_Mirroring_Monitors

You should not upgrade your device's firmware if you do not have any issues with the functionality of your device. The only time you should consider an upgrade is if you are experiencing a problem with the device, and you have confirmed that the firmware addresses this problem.  You can confirm this is the case by reviewing the documentation included with the firmware or by consulting with our Technical Support team. Incorrectly upgrading firmware can result in diminished performance so it is best to contact StarTech.com if you would like to perform this operation.

If the keys on your keyboard are repeating, complete the following:

1. If the KVM you are using has USB ports, you can move your keyboard to the USB hub port on the back of the KVM (the USB hubs are marked).

Note: When you move the keyboard out of the keyboard port, you will not be able to access the hotkeys.

2.  You can adjust the typematic rate in your operating system’s settings. Depending on the version of Windows you are running, you can adjust the typematic rate by doing one of the following:
   • Click Control Panel > Keyboard > Speed. Adjust the repeat delay and repeat rate until the keys no longer repeat.
   • Click Control Panel > Hardware and Sound > Devices and Printers. Right-click Keyboard Settings. Adjust the repeat delay and repeat rate until the keys no longer repeat.

There are some quick tests that you can perform to rule out potential issues. Start by turning off all of the connected computers and peripherals, unplugging everything from the KVM, including power, and leaving it for 10 seconds.  Then connect everything to the KVM following the procedure in the following FAQ: https://www.startech.com/faq/kvm-switches-setup.

You can test to make sure that the following components are working correctly and are not the source of the issue:

• Video cables

• KVM switch

• Video source (such as a DVR or computer)

• Video destination (such as a monitor or projector)

Note: When you are testing your setup components, it is recommended that you avoid using any video adapters. For example, if you are converting a VGA source to HDMI to be used with an HDMI extender, you should test with an HDMI source.

To test your setup components, try the following:

• Use the video cable, KVM switch, video source, and video destination in another setup to see if the problem is with the components or the setup.

• Use a different video cable, KVM switch, video source, and video destination in your setup to see if the problem persists. Ideally, you should test a component that you know works in another setup.

When you test your cables, it is recommended that you do the following:

• Test each cable individually.

• Use short cables when you are testing.

When you test the video source and video destination, it is recommended that you do the following:

• Remove the KVM switch from your setup and test to make sure that the video source and video destination work together without the KVM switch.

• Test to make sure that the video source and video destination work together at the resolution that you want to use.

Note: In order for your setup to work properly, the video source, KVM switch, and video destination all need to support the resolution that you are using.

There are four troubleshooting actions that you can try if some but not all of the ports and your computer are working with the KVM switch. 

• To determine if a specific cable is the source of the problem, switch the cables that connect the KVM switch to the computers to one working port and computer, and one port and computer that is not working. Keep the computer plugged into the same ports and only switch the cables. If the issue persists when you switch cables, the issue may be with the cable itself.
• To determine if the problem is between the computer and the KVM switch, using the same cables, connect the KVM switch to one computer that is working and one computer that is not working. If the issue persists when you switch computers, follows the issue may be with the computer and the KVM switch.
• Try reinitializing the KVM.  This is done by following the setup instructions on the website.
• To determine if the KVM switch is the source of the problem, if you have another KVM switch, disconnect the current KVM switch and connect the second KVM switch.

1. Ensure the video & USB cables are connected between each computer and the KVM switch
2. Safely power off all computers.  Unplug everything from the KVM switch and connect one computer at a time, swapping the inputs previously used (e.g., the computer connected to PC2 now connects to PC1). Power on each computer and confirm functionality before connecting the next one to the KVM switch. 
   • If using a KVM switch that supports multiple displays, ensure all video connections from the computer are from either the video card or motherboard, both cannot be used simultaneously on most systems.

Digital Visual Interface (DVI) is a video display interface that can contain different types of signaling, based on the application. DVI cables and ports are created using different connector types to identify what application they are intended to be used in. The connector types are identified by the number of pins on the DVI connector. DVI comes in the following five different connector types: 

• DVI-A (17 pin).
• DVI-D Single Link (19 pin).
• DVI-D Dual Link (25 pin).
• DVI-I Single Link (23 pin).
• DVI-I Dual Link (29 pin).

Single and Dual link DVI indicate the maximum resolution capabilities of the video source or video destination. The maximum resolutions are Single Link (1920 x 1080 @ 60Hz) and Dual Link (2560 x 1600 @ 60Hz).

Note: The maximum resolution of your video source and video destination are ultimately determined by the technical specifications of the devices. The connector type is not a definitive indicator of the maximum resolution.

DVI-A carries only analog (for example, VGA) with no digital component. DVI-D carries only digital video (for example, HDMI) with no analog component. DVI-I combines DVI-A and DVI-D connections to include both analog and digital components. A DVI-I port may be on either your video source or display, but whether or not a display carries either or both analog and digital sources depends on the technical specifications of your device.

Cables and adapters that do not align to the size specification for DVI connectors may not fit properly beside one another on this KVM switch due to the spacing of the DVI ports. We recommend ensuring the connector is 39.5mm or smaller in width, as larger connectors may not properly connect beside one another. The cables listed in the Accessories tab are confirmed to be compatible with this KVM switch. 

Whether a specific mouse or keyboard will work with StarTech.com KVM switches can depend on the type of mouse or keyboard you use.  Any mice with additional functionality or keyboards that are not standard 104 key keyboards could cause issues.  This includes wireless, gaming, combination (one USB receiver for both the mouse and keyboard), and Apple keyboards.  We recommend that you use a standard wired mouse and keyboard with our KVM switches, especially when you troubleshoot issues.

If you cannot get a specific mouse or keyboard to work with your KVM switch, connect the mouse or keyboard into the USB hub ports, if available (they are marked on the back of the KVM switch). If the KVM switch has hotkey functionality, you will lose the functionality when using these hub ports.

This device has a DVI-I connector and is compatible with both analog and digital DVI video signaling. If you have a display or video destination that uses another type of video connection, there are ways that you can convert the video signal or connection. These options are outlined below and organized by the target connection.

It can be difficult to tell which ones are right for the KVM switch you are interested in.  How can you tell which KVM cables you require?  How can you tell if a KVM switch requires proprietary cables?  How do these cables work? 

Standard KVM Switches and Cables

Note: You will need one bundle of KVM cables per computer you want to connect to the KVM switch.

Standard KVM switches have no special cable requirements.  If you have spare video and PS/2 or USB cables, you can use them to hook up the KVM switch to your computers.  StarTech.com still sells KVM cable packages, but they are just for the convenience of buying them in bundles and usually involve some savings.  Keep in mind that even if you have some of the cables you need, it still might be advantageous to buy the bundle.

KVM Switches with Opposite Gender Video Connections

Some KVM switches use male video connections for the computers and female video connections for the console ports.  In this case you simply need a video extension cable, or a KVM cable package appropriate to the KVM switch.  This is so you cannot accidentally plug cables from your computer into the console ports.

KVM Switches Requiring Proprietary Cables

KVM switches can also use proprietary KVM cables to connect to the individual computers.  This is often done with larger KVM switches and KVM switches intended for a server environment.  These cables use a proprietary pinout which does not conform to the video standard in use, as the cable carries both the video and PS/2 or USB data along a single cable.

If you are unsure whether or not you need special cables, complete the following:

1. Check the Technical Specifications tab on the individual product pages for What's in the Box.  This section lists everything that comes with your purchase, and your KVM switch might come with the cables.
2. Check the Accessories tab.  This section lists potential accessories for the product you are looking at.  StarTech.com will list the appropriate KVM cables for the KVM switch here. 
3. Check the Gallery and look at a picture of the back of the KVM switch.

Note: If there are no PS/2 or USB ports on the back of the KVM switch other than for the console, you will require proprietary cables.

If at this point you require further assistance in deciding which cables to purchase with your StarTech.com KVM switch, contact our technical support team.  

KVM stands for Keyboard Video Mouse and KVM switches allow you to switch the use of a keyboard, display and mouse between multiple computers.  KVM switches also commonly let you switch audio and USB devices between computers.

There are different types of KVM switches as well.

• Standard box KVM switches. (e.g. SV231USB)
• Cable KVM switches. (e.g. SV211USB)
• Multi-Monitor KVM switches.  (e.g. SV231DDUSB)
• IP KVM switches. (e.g. SV841HDIE)

Standard box and cable KVM switches are a simple way to switch the use of a keyboard, display, and mouse between multiple computers.  Multi-monitor KVM switches allow you to switch multiple displays between computers, and IP KVM switches allow you to remotely control the KVM switch and connected computers over a network.

Here are some important things to consider before purchasing a KVM switch.

• How many computers do you need to control?  Purchase a KVM switch that supports the number of computers in your setup.
• Which video connections do your computers and display(s) support?  It is best practice to use the same video connections wherever possible.
• Will you be using a PS/2 or USB mouse and keyboard?
• Do you need multiple monitor support?  Ensure every computer can support the number of monitors you are looking to use in your setup.
• Do you need audio support?
• What resolution(s) do you want your display(s) running at?  The KVM switch must support the resolution(s) you want to use.
• Would you like hotkey support?  Some KVM switches support the use of hotkey combinations to complete tasks such as switching between computers.

There are a couple of other important things you may want to take note of:

• Some KVM switches require proprietary cables to function.  These KVM cables may vary by each KVM switch.  For StarTech.com KVM switches that require proprietary cables, the KVM switches will either come with these cables, or they will be listed in the Accessories tab on the individual product pages.  For more information, see our video dedicated to KVM switch cables.
• Basic mice and keyboards are recommended for use with KVM switches.  Wireless, gaming or combo mice and keyboards (mice and keyboards that use a single USB connection / receiver for both units) can cause performance issues, and in general, are not supported for use with KVM switches.

1. Turn off all of the computers and monitors that will be connected to the KVM switch.
2. Connect the power adapter to the KVM switch.
3. Connect the video cables from your monitors to the console video port on the KVM switch. 
4. Turn on the monitors.
5. Connect your keyboard and mouse to the console PS/2 or USB ports on the KVM switch.
6. If you have not done so already, change the KVM switch to focus on port 1.
7. Connect the video cables from PC1 to the KVM switch.
8. Connect the PS/2 or USB cables from PC1 to the PC1 PS/2 or USB ports on the KVM switch.
9. Turn on PC1. You should see the computer load the operating system that you are using on PC1.
10. Make sure that the mouse and keyboard can control PC1.
11. Repeat steps 4 to 8 for each additional computer that you want to connect to the KVM switch. Leave the computer in focus until you make sure that the mouse and keyboard can control the computer in step 8.