M403 Generic 10 Amp Fuse 5 x 20mm Cartridge Type, Universal Replacement Fuse for Appliances and Electronics

M403 is a generic 10A cartridge fuse in the standard 5 x 20mm size. Fuses this size turn up on appliance control boards, power supplies and a wide range of household electronics. It isn't tied to one brand, so the thing that matters is matching the old fuse: the same 10A rating, the same 5 x 20mm body and the same blow characteristic marked on its end cap.

Why a 10 amp fuse blows

A fuse is a deliberate weak link. When current climbs past its rating, the thin element inside melts and breaks the circuit before wiring or components overheat. An appliance that's suddenly dead, with no lights or display, often has a blown fuse somewhere in its supply. Look for a broken wire or a darkened body, or test it for continuity with a multimeter. Keep in mind a fuse usually blows for a reason. If a new one fails straight away, there's a fault such as a shorted motor, element or board that needs tracking down.

Part details

• Generic fuse, stock code M403
• Rated at 10A
• 5 x 20mm cartridge body
• Universal part, not made for one brand

Replacing a fuse safely

Unplug the appliance or isolate it at the switchboard before opening any covers. Some boards hold large capacitors that stay charged after power is removed, so avoid touching components. Never fit a higher rated fuse than the one you take out, and check whether the old fuse was fast acting or time delay. If the replacement blows again, stop and have the fault diagnosed by a qualified technician.

Questions about this part

Can I use this fuse in place of a lower rated one?

No. Always fit the same rating as the fuse you're replacing. A 10A fuse in a circuit designed for less won't protect it, which can lead to overheating or fire. Match the size, the current rating and the blow type.