Can you post the model number of the appliance please?
When you try to use the appliance now on a new programme, what exactly happens?
If the drain pump is running all the time and no error code is ever shown by flashing lights, it would suggest a problem with the main control board.
Unplug the appliance.
Take the rear cover off.
The main control board is bottom left when viewed from the rear.
Take the board out and one plug at a time, unplug, check it's clean, dry and tight fitting, plug back on.
Check the board for any obvious damage.
Refit the board and try the machine again.
Let me know what happens.
Sorry you didn't find the service helpful.
Unfortunately I'm not able to predict when a post will be made nor can I tell if you are actually working on the appliance.
My last request would have needed the machine to be working so not sure what you mean by "keep the machine dismantled" as there's nothing in your question to intimate that the machine is in bits.
There is no live chat so unless you pass specific information to us, we won't know when you intend reading our posts or responding to them.
I'll opt out of your question now and open the question to all experts again.
Perhaps one of the other experts will pick the question up when they finish work tonight.