I've got a laptop with HDMI output that I'm trying to connect to my projector with VGA input.

I've got a VGA cable, as well as a dongle that says this in the online description: "This product is a portable digital-analog conversion line, defined through a standard HDMI input HD sources, you can convert HDMI video output to VGA"

It's not working. Have I got the right HDMI to VGA cable? Is it just that my VGA cable is faulty? I don't have any VGA-output devices that I could test the VGA cable with.

The projector works well when just projecting the "no signal" screen, or the menus, so it's not a matter of a broken projector (although maybe it's a broken input?)

I'm just trying to figure out whether I have the right dongle. This is the one I have:

https://www.amazon.co.uk/gp/product/B009CRN810/ref=oh_aui_detailpage_o05_s00?ie=UTF8&psc=1

Does your cable plug into the product? Was there a driver for it?

I don't use a laptop so I may be mistaken but if it were me I would look in the bios to see if there was a setting to either enable HDMI or to set it as my video out. VGA cables do not just go bad unless pins are missing or bent.

Keep in mind, what may be happening is you are trying to drive the VGA projector at resolutions far beyond what it is capable of, particularly if its an older projector.