You could try to restore it. First thing - replace all of the caps on the board and the power supply. Then go from there. Maybe the laser isn't working at full power because of bad caps? That might explain the light printing. It also might explain dark toner on the paper. toner goes onto the drum to rub off on the paper and the fuser then melts it. The laser makes the drum more magnetized - so that's where it picks up the toner. If the laser wasn't working, you might see uniform black on the page. If the fuser wasn't working,, you would see "loose" toner on the paper.
So replace caps first, then see if the fuser is working. If you get solid print on the paper, but it's nor printing what you say then you've got a laser problem. Good luck.
So replace caps first, then see if the fuser is working. If you get solid print on the paper, but it's nor printing what you say then you've got a laser problem. Good luck.