Hi, I am attempting to connect my YOGA laptop to an external monitor with no success. I suspect that the USB link to the monitor is incorrect and that I should be using the C port instead - except that I don't currently have the cable that will link between the computer and the monitor cable. Any advice would be much appreciated. Thanks 

Welcome to the community forum.

What is your system's type (e.g. IdeaPad 5 15IIL05) and 10-character MTM number (e.g. 20H1CTO1WW)? One way to obtain these is from the main page of Lenovo Vantage. Do not post the serial number. See How To Locate Machine-Type Model (MTM) Number for more information.

Also,

1. what is the make/model of the monitor?
2. what ports are you using on the Yoga and on the monitor?
3. have you tested if the monitor and cable work with other systems?

Hi, thanks for the quick response, much appreciated. The questions are a bid complicated for an old fart like me (I was born in 1943), however this is what I can say:

1. The make is LEVONO YOGAS 900 131SK
2.  the monitor is a SAMSUNG SyncMaster 940nw
3. The port I am using on the laptop is the second UDB port on the left-hand side. The monitor has a standard cable attached with a male screw-in end.
4. No, I haven't tested "if the monitor and cable work with other systems?"

Lawrie

Note to worry. I'm not much younger ;)

2. the monitor is a SAMSUNG SyncMaster 940nw

This model has only a VGA port. That's the screw-in plug you referred to.

1. The make is LEVONO YOGAS 900 131SK

The Yoga 900 supports VGA monitors using its USB-C port. According to the specs, "optional VGA port (via USB 3.0 Type-C to VGA adapter, sold separately)"

You will need a cable similar to this https://www.amazon.com/Plugable-ThunderboltTM-Supports-Resolutions-1920x1080/dp/B072DX5Z5S 

The cable should have connectors that look like this

If this isn't what you are using then I'm curious how you are connecting the external monitor to the Yoga.