HP 1020 laser printer emitting smoke when printing?

It could be toner or electrical, I would discontinue use until you resolve the problem? One you turn on the printer it requires a drum to heat then the toner is applied and is fused to the paper by heat. but this warm up cycle should prevent you using it until the warm up is complete? Be careful handling the toner cartridge it is carcinogenic and poisonous, hazardous to your Health if inhaled

Change your old cartridge with new one. It may solve.

Thanks

No need to let it heat up, seems to be doing that O K.

nothing to worry

its just due to moisture