Clear debris under the bed and around the rear fan before printing. Clean the PEI surface and inspect the nozzle for a plastic blob that could spoil probing.
With power off, check V-wheels for play and flat spots, belts for damage and cables for rubbing. Adjust only when the Elegoo procedure and actual movement show a problem.
Wipe lead screws before applying the lubricant Elegoo specifies. Keep oil away from belts, wheels and the build surface. Spin each Z screw through normal motion after service and rerun leveling.
Stop for unstable temperature, damaged heater wiring or repeated probe failure. Record firmware, service dates and nozzle changes so later faults have context.
Routine cleaning only goes so far when the nozzle itself gets partially blocked — the general clogged nozzle clearing guide covers that situation safely. If a nozzle is worn out rather than clogged, the nozzle replacement steps for this Pro pick up from here, and persistent heating or probe faults are best checked against the Neptune 4 Pro warning index. The same routine checks are the closest documented reference for the newer Neptune 5, which doesn’t yet have its own maintenance page.