Hi, Warren!
You would have to suspect a wiring fault if all just stopped at once. I'm not that familiar with pop tops, but you should find some sort of flexible cable running from the bottom section of the van to the roof. If that looks OK physically, i would need to know what sort of fluoros they are. Do they work without mains voltage or not? If they run from the battery, you could check the 12v with a test lamp. You may also need to check for a blown fuse. I'm also sure that there must be Coromal pop top owners out there who may be much better help than I can. It's probably a burnt wire connection somewhere, and if that's the case, finding it can be tricky.
Regards
Chris

There is a Coromal facebook group . You should get a reply if you post there. There a few Coromal service people who can help

www.facebook.com/groups/coromal/

Im guessing you checked the fuses ??
My coromal has a very comprehensive array of fuses

On pop tops there is usually a lead that connects the power to the lights in the roof. It usually plugs into a point in one of cupboards around the top of the van. Check this plug to make sure it hasn't come out of the socket.