Indesit-WIB111 does not start

Washer Repair
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1

Brand:Indesit
Model Number:WIB111
Main Symptom:Lock door
**What happens & when:**Here is the translation into English:

Hello, I have a washing machine Indesit WIB111. It is plugged in, water can flow into it, the hose is not clogged. As soon as I plug the washing machine into the socket, the door locks immediately. That shouldn’t happen. It only unlocks 2 minutes after unplugging the machine from the socket.

I press the On/Off button, the red LED lights up as always on the front panel. Then I press Start and the green LED lights up, indicating the first washing phase will begin. For a fraction of a second you can hear the pump trying to engage, but then nothing happens. If I press and hold START, the program resets, the machine doesn’t unlock even after 5 minutes, but after some time the pump starts running.

I disassembled the machine and tried applying 230V directly to the pump — it works. The carbon brushes are OK. The pressure switch is OK and the hose system has been cleaned out. The water inlet valves are fine too. At the start, the machine should begin filling with water, but it doesn’t fill. I tested both valves outside the machine and both work. The door lock reads 1.1k Ohm resistance between pins 2 and 3. It carries voltage immediately when the machine is plugged into the socket. Contact 4 closes. The heating element is OK. The motor is also OK.

I currently have the control board disassembled. I have tested all the relays and the triac on the heatsink.

The fault was preceded by a power outage. The machine had probably already finished or was mid-spin cycle (the laundry was spun).

I don’t know what to do next — can you advise?

I am also attaching the control board schematic. The schematic is not exactly for my model of washing machine, but apart from 5 components which I have marked with a green dot, they are identical. The red dot indicates the triac with heatsink, which I desoldered and verified its functionality using a circuit with a light bulb, resistor and 12V supply.

Name of my main board modul is EDT0117.7. The schematic plan is EDT0117.11

Thank you

edit: i have changed schematic

Error Code (if any):
Parts or tests already tried: Triac on heatsink. 4 relays

Arcadia_EDT0117.11_schABc
Arcadia_EDT0117.11_schABc1920×1357 542 KB

Photos / video link:

2

I disconnected the gate (G) of the triac mounted on the heatsink, which controls the door lock. After powering the washing machine, the door does not lock. When I connect the gate (G) directly to the PCB, the door locks, and when I break this connection, it unlocks again. This suggests that the triac is probably fine and that the microcontroller is communicating with the gate (G).

There are two transistors between the gate (G) and the microcontroller. These transistors likely control the signal to the gate. I’m not sure how to interpret this.

I don’t know how to proceed. I feel stuck. Should I focus on those transistors, or on the microcontroller?

Thank you.

3

From what it sounds like, the focus should be on the entire control board itself. If this appliance has not produced an error code indicator, it would suggest the control board is unable to perceive the failures that are occurring. Usually, this would be caused by an issue in the program of the control, with a possibility of the built in processor being damaged.

4

To summarize everything I have measured and what I have found regarding how the faults manifest.

When I plug the washing machine into the mains, within a few seconds the door lock engages. When I close the door, the lock clicks and does not release until I unplug the machine from the mains. The triac that controls the lock is triggered by a transistor, to whose base the processor supplies 1.76V. I replaced the ULN2003 circuit that drives the relays. The relays are functional and switch voltage as they should. I tested the motor directly on 230V and it runs without issue. The valves allow water through when 230V is applied directly to them. I removed the heating element and tested it by heating water in a bucket. The door lock itself switches correctly — when the bimetal strip heats up, it bends and connects the phase to another contact of the lock. The pressure switch HD505 KB01 closes its contact when the water rises to a certain level. The pressure switch outputs 5.5V, but only 2.76V reaches the processor because the signal passes through 2 resistors. The temperature sensor has a measurable resistance, as does the tachogenerator — which additionally produces approximately 2V AC when the motor is turned by hand.

What is unusual is the following: when I select a wash program, press Start, and manually engage the door lock, the fill valve activates for approximately 1 second, then shuts off, and then exactly 20 minutes later the pump starts and runs for 5 minutes before switching off. While the pump is running and afterwards, the door lock LED flashes rapidly and the RAPID WASH LED flashes somewhat slower. Inside the machine there are reportedly 2 additional LEDs on the panel which represent values 1 and 2 in the error code system. The ANTI-CREASE LED on the front panel represents 3 and RAPID WASH represents 4. Neither of the internal LEDs is flashing.

I filled the machine with water so that the pressure switch engaged. I let the machine pump out the water, but nothing improved.

When I set the spin-only program, pressed Start and engaged the lock, the motor immediately ran for 1 second and then stopped. When I set the drain program, the pump ran for 1 second. And if left in that state, the pump always starts after 20 minutes. The pump activates when the relevant processor pin sends voltage to the relay (via ULN), regardless of whether the pressure switch is outputting 2.76V or not.

I measured at the processor and ULN2003 that the signal to start and then stop after that one second is sent by the processor itself.

I also replaced the electrolytic capacitors.

The 12V and 3.3V supplies maintain stable voltage even under load. The processor receives 3.3V at idle and in fact at all times. There should be no leakage anywhere — the board has been cleaned. No component shows any visible signs of burning.

A long press of START resets the current program.

The machine behaves as though it believes there is still water inside, or for some reason decides to engage the door lock as soon as it is plugged in. Yet when the pressure switch is not engaged, the relevant processor pin reads 0.19V. When the pressure switch engages, it reads 2.76V.

I would like to know what the error code means, and also whether there is any hard reset to factory memory settings.

Thank you