Samsung WW90 washing machine won't turn on – diagnosis

SAMSUNG WW90 range · freestanding washing machine · based on 61 similar repairs

Diagnosed by Sean McCauley · SMC Services · Last verified 10 May 2026

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Likely causes (Samsung freestanding washing machine):

Pcb — 60.0% of cases
Pump — 13.3% of cases
Drain Pump — 8.3% of cases

Problem summary

Your Samsung WW90 washing machine is not responding to power. The machine will not start, and there are no lights or sounds when you press the power button or control panel.

Likely causes

Based on 62 repair records for this fault pattern, the most common causes are:

Printed circuit board (PCB) failure – accounts for roughly 62% of cases. The PCB controls all functions of the machine. If it fails, the entire appliance will not respond to input, even though mains power may be reaching the machine.

Pump malfunction – found in about 13% of reports. A faulty pump can trigger a safety lockout that prevents the machine from starting.

Door seal or latch issue – accounts for roughly 8% of cases. If the door sensor detects a fault, the machine may refuse to power on as a safety measure.

Why this needs an engineer

All three likely causes involve electrical components (PCB), sealed mechanical systems (pump), or safety interlocks that require specialist diagnosis and replacement. A qualified engineer will need to:

Test the mains supply to the appliance and check for electrical faults
Inspect the PCB for burn marks, corrosion, or component failure
Check the door latch and seal for blockages or damage
Test the pump for continuity and mechanical integrity
Replace faulty parts and verify the repair

Attempting to open the machine or test internal components without proper training risks electric shock, water damage, or voiding any remaining warranty.

What to check before calling

Ensure the machine is plugged firmly into the wall socket and the socket itself is working (test with another appliance, such as a lamp).
Check that your home's circuit breaker or fuse for that socket has not tripped.
Look for any visible water leaks or blockages around the base of the machine that might have triggered an automatic safety stop.

If the machine still will not respond after these checks, a fault with the PCB, pump, or door sensor is likely.

When to call SMC Services

Contact a qualified engineer as soon as possible. The sooner you get the machine checked, the sooner you can rule out a simple electrical fault or identify a part that needs replacing.

If you're in Northern Ireland, SMC Services can usually book a repair within 2-3 working days.

Step by step

Check mains power and circuit breaker. Plug another appliance (lamp or phone charger) into the same wall socket. If it works, the socket is live. If it doesn't, check your home's circuit breaker or fuse box and reset or replace as needed.
Inspect the door and seal for visible damage. Open the door fully and look for cracks, tears, or visible debris in the seal. Check that the door closes firmly without gaps. If you spot damage, the door switch may be preventing startup.
Look for water leaks or blockages. Check around the base of the machine and underneath for pooled water or debris. Some models have an automatic safety lock if a leak is detected, which stops the machine powering on.
Call a qualified engineer if checks pass. If the socket is live, the door looks intact, and there are no leaks, the fault is internal—likely the PCB, pump, or electrical connection. A qualified engineer must diagnose and repair.

Frequently asked questions

Could a blown fuse or tripped circuit breaker be the problem?

Yes, it's worth checking first. Ensure the wall socket is live by plugging in another appliance. If the socket is dead, reset the circuit breaker or replace the fuse. If the socket works but the washing machine still won't respond, the fault is inside the machine itself.

Is it safe to open the back panel and look for loose wires?

No. The PCB and internal components may still carry dangerous voltage even when the machine is unplugged. Opening the machine without proper tools and training risks electric shock. Always call a qualified engineer.

If the PCB has failed, do I need to replace the whole machine?

No. The PCB is a replaceable component. An engineer can diagnose whether the PCB is faulty and fit a new one, which is usually cheaper than buying a new washing machine.

Why would a door seal problem stop the machine powering on?

The door latch contains a safety switch. If the switch detects that the door is not properly closed or the seal is damaged, the machine's control system may lock out to prevent water leakage. The machine will not start until the fault is resolved.

Get this fixed

The parts most often needed for this repair — order direct:

Fits your WW90 Samsung Main Pcb (DC92-01640G) £99.23 SMC05912 View part → Fits your WW90 Samsung Main Pcb (DC92-01768D) £86.82 SMC10912 View part → Samsung Assy Sub Pcb (DC92-00599A) £91.33 SMC02412 View part → Samsung Assy Pcb Sub (DC92-00773G) £88.38 SMC02416 View part →

Browse all spares

Prefer a pro? A local appliance engineer can carry out this repair. SMC's own repair service covers Northern Ireland only. The parts above ship UK-wide.

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About the data on this page

This page draws on 61 similar repairs from across 29 years of SMC Services records — over 116,000+ appliance repairs in total since 1997. The likely-cause percentages above are computed directly from the engineer reports we filed for this brand and fault, and we update them as new repairs come in.

SMC Services Ltd · Registered in Northern Ireland, Co. NI628091 · Domestic & Commercial Appliance Repairs.