Bosch Dishwasher SGV53E03GB/50 Constantly filling and Draining all LEDs lit up for

[msanman]

Hi I have a small problem with the dishwasher constantly filling and then forced draining due to reaching water height limit. This repeats as soon as Start Button pressed if door open or closed, but stops when start button pressed to stop. The bottom sump overflow switch is dry. The wash temperature programme buttons LEDs 70 65 50 and 35.are lit up thats L1.to4 but not rinse LED L5 that’s off . I can’t distinguish them. When I try holding down and reset buttons L2 and4 the LEDs just dim slightly. Tried holding Start Button for 7 and 15secs with mains power on off but not able to reset the control panel. There is a tech sheet for fault codes SO-60/0686 that shows leds on L2 L3 and L3 unassigned fault code. I removed the pcb control panel and that looks perfect no visible burning or cracks in solder. So now stuck ! I don’t know the flowchart of dishwasher operation to know what to check e.g. After water enters float chamber then is it the Aqua sensor starts the heater or circulation motor for me to test voltages of sensors on the PCB and what relay should be activated. Any help welcome please. I have the cct diagram and wiring diagram:-)

[msanman]

Attached Service Test Programme sheet S0-60/0686. The PCB Control Panel Part No was 00492685 and latest code is 00442394. I understand it fits other Bosch/NEFF models too

[electrofix]

check the left hand side where the fill system can get gummed up causing these sort of problems

Dave

[msanman]

Thanks Dave for the advice. I opened the left panel and gave the pressure float chamber a good scrub. Checked the micro siwths with meter for the level pressure water switch (Diagphram type as dont have a water flow switch), watched the fill and drain sequence occur. Still got no repsonse from control panel buttons LEDs 1 – 4 still illuminated. What occurs after the dishwasher fills and the pressure/levle switch (e6)is activated does it initate a relay to start the circulation motor ? I dont know the operation sequences to fault further ? Can I hard reset the PCB bu earthing a particular pin on the board as looks locked up to me 🙂
Can I disonect the control panel cable plugs on the PCB to determine what is lighting up the LED’s. Would it be the heating element ?

[electrofix]

does sound like a board fault

have you checked for bulging capacitors on the board?

Dave

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