Error Code E51 and E50 on Zanussi WJS1265 W

Hi,

I’ve been having drain problems on my Zanussi WJS1265 W washer dryer that I finally got round to clearing today. I laid the machine backwards at about 45{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} and took the drain pump off. Checked the pump on the bench (all ok) then found a blockage in the drain hose. I cleared this with some hot water, then blew the hose clear by mouth.
After putting it back together the door latch clicks every second when the door is open. Closing the door latches it then the machine shows the “- – -” as normal. I can select a program but it won’t start, just the green light flashes.
Entering the test mode (Power on / start / reset) as soon as I select a test mode, E51 shows (sometimes E50). I can’t clear this.
I’ve double checked that all connections are still intact and that when I blew the pipe out that the MPU didn’t get wet. All appears OK.
Any suggestions what I can check. I have a Fluke 87 and am an electrical engineer on genset control panels, so can test for anything you suggest.

Thanks in advance

Tony