Hannspree tv

This is a very difficult question to answer without knowing more info, but here goes:

Check the power cable, there should be only place to plug it into. This may be one of several styles depending on your model, usually a 3 prong female (just like your PC's power cable) connector, or a single pin female connector (looks male but has a hole in the center) will connect to the back of the monitor.

If you get power, but no image: VGA connections will use a large blue connector with 15 round pins, 3 rows of 5. DVI will be a large white connector with slotted pins, with varying amounts of pins depending on the type of cable (analog, digital, or both). HDMI will be a small connector that resembles a large USB connector. You may also be using a composite or component cable, which will be color coded to the ports on the monitor.

All styles of connectors will physically only connect to the corresponding port. Check all connections and make sure they are all secure and connected to the correct locations on the monitor. Doing this should resolve your issue.