Poor print quality can be caused by a number of things, including a bad toner cartridge. If the drum is bad, no quantity of toner will make the thing print properly.

If there is a big physical difference between the two cartridges that came with the machine, there is something wrong. The HP and Apple OEMs are physically identical, and in fact, neither company manufactured the original engine, which was a Canon.

Failure to start up can also be caused by the bad or badly seated toner cartridge.

Given these three facts, maybe the place to begin is with a remanufactured toner cartridge; if it still fails to work when that is installed, sell it on again.