Have you replaced the batteries?

Also, you can "reboot" the remote by removing the batteries for a minute and putting them back in.

I want to check out whether it's the remote or the receiver that's at fault, by using a universal remote.

There are also a few other ways you can check, as described here. That's for a different remote, but most of what's in there applies to any remote. My favorite way of checking is by looking at the front of the remote with my digital camera.