Parts for WP3900 — Brother

We found 12 parts confirmed to fit the Brother WP3900.

Compatibility table

Prices shown are an informational reference range only, not an offer or an Amazon price — RepairKitHub does not sell parts directly. Each part links to an Amazon search so you can compare current listings yourself.

Common failure areas on this model

The confirmed parts above group into a handful of failure areas. Here is what each points to and how to check it before you order anything.

General hardware and mounting parts

Symptom: A small mechanical or mounting part has failed, cracked, or gone missing.

Check: Compare the physical shape and mounting points to the original piece, and confirm the exact part number against your model plate before ordering.

Parts in this group on WP 3900: 321538401 (Blanket), 50MH500524 (Scroll), 6693899 (Throttle Wire), WPW10108260 (Control), B199 (Type Ribbon).

Storage, trim and cosmetic hardware

Symptom: A cracked shelf, broken door bin, worn hinge, or missing trim piece -- cosmetic and storage wear rather than a functional breakdown.

Check: Match the physical dimensions and mounting tabs of the old part before ordering; these pieces are often model-specific even between visually similar models.

Parts in this group on WP 3900: X33401631 (Home Electronics Panel Assembly), 93700040060B (Screw), WB09X10036 (Torsion Spring), W10836964 (Refrigerator Evaporator Drip Pan).

Controls, timers and wiring

Symptom: A cycle that doesn't advance, an unresponsive display, or the unit not starting at all.

Check: Look for burn marks or a burnt smell near the board or terminals, and check whether buttons and knobs respond -- a unit that powers on but won't cycle often traces back to this group.

Parts in this group on WP 3900: DC9201989B (Washer Electronic Control Board).

Water inlet and drainage

Symptom: The unit isn't getting water when it should, or isn't draining or pumping it out when it should.

Check: Check the valve or pump for a clog or jammed object, and confirm the hose isn't kinked, restricted, or routed higher than the unit allows.

Parts in this group on WP 3900: 807047901 (Dishwasher Water Inlet Valve).

Door, lid switches and latches

Symptom: The appliance won't start, or stops, unless the lid or door is fully latched shut.

Check: Listen for an audible click when the lid or door closes. No click, or a visibly cracked plastic tab on the latch, points to this part.

Parts in this group on WP 3900: DC6400828B (Dryer Door Switch).

Before you buy

Match WP3900 exactly against the model and serial plate on the appliance itself before ordering anything — a single mismatched character can point to a different production run with different parts. Then check the part number printed or stamped on the part you are replacing against the part numbers in the table above; the printed number is the most reliable way to confirm fitment when a model has gone through multiple production runs. RepairKitHub does not sell parts directly — every part link above routes to an Amazon search for that part number so you can compare current listings and sellers yourself.

How to confirm this is your model

Check inside a door opening, on a back or side panel, or behind a removable panel or drawer for a label printed with the model and serial number. Match every character exactly, including letters and dashes at the end — appliance model numbers often have similar prefixes but different suffixes for different production runs.

Still not sure?

Use the model lookup tool to search by model or part number, or start from the symptom your appliance is showing.