TEKA DW6 55 FI dishwasher Beeping 10 times & not working?

I have a TEKA DW6 55 FI dishwasher, which is not working.
Symptoms are that when turn on power, select any programme, & shut the door, I get a hum/noise of the machine, but then 10 beeps, followed by pause and continuously repeated. Opening the door shows the 4 or 5 lights from the lefthand side flashing (the programme lights). Noting else happens. No water starts to flow.
Power is on. Water is on.
I have checked water inlet hose filter – clean.
I did have water in the tray underneath the machine and have now sponged out all that water so that the float sensor appears to be down. Same symptoms still.
I have taken off the right hand panel, disconnected the air hose, blown down it, and see bubbles in the sump inside.
I have placed water in the sump, started a programme, and the pump does empty this, with obvious water pressure coming out of the drain hose, so the pump appears to be working on the face of it. Is that right – does the pump operate to remove waste water ?
I’m not a professional, and have tried the ideas above I have found online. I’m looking for further suggestions as to what is still causing the beeps/fault.
I saw some online advice to ‘reset’ the machine by holding down the on/off button or a programme button until hear a beep, but I didn’t seem to get this.
Thanks for any help in advance.