Left is a relative term, but I'm going to treat this as you are printing in portrait mode and scanning left to right across the page.
How much Toner is left in the cartridge? Voids can be due to low toner, but usually get worse as you print.
Fusers do not cause voids, the toner would be there but no adhere to the paper and would smear when wiped.
Do a half self test:
Load paper in Tray 1
Print a test page, it should feed from Tray 1
When the paper is almost fully into the machine pop open the Toner Access Door, that will stop paper motion.
Open the door, remove the cartridge
Inspect the page while it is still in the printer, if you see voids it is not the fuser, you are looking at an unfused image.
If you see voids on the paper then flip over the toner cartridge and pull back the shutter, you can see a faint image where toner has already beentransfered off the OPC Drum and a darker image where the toner has not been transfered.
If there are voids on the Drum then replace the cartridge as it's highly likely that is the problem.
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