If you have set up a new PC and are having problems getting a display from your monitor, here are a few things to check:
1) If your PC comes supplied with a graphics card, check that you have plugged your monitor into one of the outputs on the graphics card. It won’t matter which output you use as long as it’s one from the graphics card and not one of the outputs from the PC mainboard. The graphics outputs on the PC mainboard are disabled when a graphics card has been installed.
2) Check your HDMI cable meets the required standard. Older HDMI cables which meet HDMI 1.4 or older may no longer work with modern graphics cards because the supported bandwidth of the cable is not high enough to meet the demands of current TVs and monitors. Sometimes an image will be displayed but keep dropping out to a blank screen, and sometimes there will be no image displayed at all. Other issues include artefacts, video and audio glitches and synchronisation problems. Ideally, you should choose an HDMI 2.0 or 2.1 cable as these will give the best results. Alternatively, use a DisplayPort 1.4 cable as these should provide similar quality to HDMI 2.0.
3) VGA connectors are no longer supported on modern graphics cards as they are analogue. Some mainboards have VGA outputs onboard, but these will only work in systems sold without a dedicated graphics card installed. Where a graphics card is installed, the VGA port on the mainboard will be disabled. It is possible to buy HDMI to VGA adapters which will allow a VGA monitor to be used but remember that only resolutions up to full HD 1920 x 1080 can be supported.