On 15/02/2018 07:33, Brian Gaff wrote:
Well several things really. Where have they been stored. What is the state
of the toner, could damp have got in? The drum is often part of the toner
cart so try a new one. The corona wires can and do get corroded as well and
of course the high voltage generator could have been compromised by damp or
merely by deterioration of capacitors in the power supply.

Brian


Since nobody has mentioned it yet, have you put new paper in? I have
taken an HP laserjet out of the cupboard after 5 years and had it print
flawlessly, so something has deteriorated in your case. Most likely is
the paper.

Give it a good clean. Failing that, try a new toner cartridge.