This is very fixable & easily tested. I doubt its the controller.
The units built with the grey controller, are built like battleships not damp toilet paper.
I cannot recommend you follow this procedure, because you do need to pay attention, but here's how I would test it.
Before you start....
Stand the BM right way up & empty. Plugged in and 'ON'.
Remind yourself how to turn the pump on in manual mode. (press 'Manu' hold for 3 then use 'P')
Be careful with 'M' -
DO NOT PRESS this with an empty machine!! 'M' turns the heating elements on - AND THEY MUST BE IMMERSED.
To test.Tip the machine upside down
Split the pump. By undoing the large brass collar.
Before you do anything else. Lift out the magnetic impeller.
Be
VERY careful with the impeller. If you drop this it will not necessarily break, but it won't ever work properly again. Members have proved this in the past.
Make sure all the tiny holes in the impeller are clean - 100%.
Put the impeller somewhere safe. Away from the BM & not on the floor
Now Press the 'P' button.
Does the 'P' light come on?
NO - The light signifies a controller issue - either the button or the relay.
YES - The 'P' light coming on signifies the controller is turning the pump on. But we need to Double check it.
Is the pin in the middle of the pump spinning?
YES - Reassemble. The pump needed a clean and probably the wires have re-seated
NO - Check the connection to the controller. It looks like a grey kettle plug.
If you cannot make the pump buzz or spin - You have found the problem – the pump. Double check it.
The double checkRemove the pump lead from the controller.
With simple multimeter check the voltage on the back of the controller. It should show Something in the range of 220/240 in the UK
YES - If the voltage is present you have confirmed the pump has failed.
NO - If the voltage reads 0 does the 'P' light come on
ON - controller issue - probably the relay. Remove controller and inspect.
OFF - controller issue - Remove controller & check the button, LED & whole board.
The most likely offender is the pump.
I seem to recall MINE is a Lowara E1-15/70B pump. Non specialist & available including shipping for below £100. **BUT MAKE SURE THIS IS THE CORRECT ONE FOR YOUR MACHINE **
ITT also make one.
Let me know how you get on !