It might sound like a strange question, but I noticed that my printer is folding paper. So I would like diagnose it, whether it's because of cartridge or the problem is somewhere else.

If I could put paper through printer without cartridge inside, and it still would be folded then it would clearly be the problem with printer itself.

Printer is HP M125nw. Basically I would like to make sure, that folding is not because of cartridge.