Warning: if the dishwasher power switch is on this board will have live mains (230V) PCB traces which are a shock hazard. Only access this board if you know what you are doing. It may also void your warranty.
The underside of the controller board. The large chip is the MCU (Renesas 6433662B94H). The triacs near the connector at the bottom of the photo are a 4 Amp STMicroelectronics T4-0560 (large triac on left) and 5 smaller triacs: Z7SY424 (also ST Microelectronics, but sorry can't find the datasheet). The triacs are located on the neutral (N) side of the load so the inputs to these triacs float at 230V AC when off.
I don't know what the 8 pin IC to the left of the MCU is – I'm guessing an EEPROM. The microswitch is the "Delayed Start" front panel button. The connector at the top-right connects the LEDs and switches on the left side of the dishwasher's front panel. The large traces at the bottom left provide power for the water heater.
This photo is the top side of the controller board. Visible are: black relay for heater on left. Buzzer (black disc in the center). The white wire pair connecting to the board at the bottom of the photo is (I believe) the water intake flow meter. The black wire pair I guess to be a temperature sensor. The blue component just above the barcode label is a combined crystal/capacitor for the MCU clock. Misc components to the left of the board are a mains to DC power supply for the low voltage electronics.
The 4 pin header to the right of the buzzer seems to be a diagnostics port. Pins on this header from left to right connect to the MCU's NMI, RXD, TXD. The last pin I'm not sure about. I thought ground would be the obvious choice, but I was seeing -5V on RXD and TXD relative to this pin. Maybe it's a +5V. This needs to be investigated further another time.
This is a close up shot of the MCU. The first digit is a '6' is difficult to see in this photo. The marking is 6433662B94H.
This is what I could figure from the mains voltage (230V AC) connector on the controller board:
White, Gray and Brown are sense wires (MCU senses presence of 230V AC or not). Blue, Red/Blue, Black, Violet, Red and Cyan drive a load (motor or actuator).
|Orange||Provides 230V AC power to the board.|
|White||Sense: ? water pressure -- it can sense if wash arm is obstructed|
|Gray||Sense: Salt related ?|
|Brown||Sense: float switch on drip tray – triggered in the event of a leak|
|Blue||Wash pump motor|
|Red/Blue||Lower wash arm valve|
|Red||Water intake valve|
|Cyan||Detergent release door|
My 'howto' on unsticking the FDW60 drain pump:
Interesting dishwasher application note from Renesas:
Excellent dishwasher hack here ("Arduino Controlled Dishwasher"):
Please add any additional information or corrections in the comments below. Thanks!