HP 51.00 Error
What it means
A laser or beam-detect error inside the printer's optical assembly. It usually indicates a hardware fault rather than something adjustable, though a power cycle is worth trying first.
A full step-by-step guide is on the way
We publish guides only after checking each step against the manufacturer's own documentation, so this one is still being written. In the meantime, if the code relates to a jam or an obstruction, switching the printer off, unplugging it for a minute, and checking for anything stuck resolves a large share of cases. For a hardware fault, contact the manufacturer.
Official HP supportDifferent code or problem?
Switch off and unplug a printer before reaching inside it. If a fault involves the power supply or internal electronics, or the machine is under warranty, contact the manufacturer or a qualified technician. Full disclaimer. Brand and code names are trademarks of their owners; PrinterFixUp is independent and unaffiliated.