Answer:
Replace the toner cartridge
Explanation:
solution
when laser printer print black color liner vertical line print it is very frustrating that condition nearly empty toner cartridge
but first we clean the corona wire for that color line
and Reinstall the toner cartridges after Shake the toner cartridge side to side
if problem not solve than Clean the drum unit
and finally if not solve change the toner cartridge
so as that our problem will be resolve
