Danby not draining not drain pump or anything obvious

Hi I was looking for some help with a problem dishwasher. It's a danby portable and it keeps stopping after wash cycle and not draining. It's a portable I did have it plumbed in permanently with a few minor alterations and has worked fine for nearly 2 years. It stop's and beeps 20 times roughly on every program I've tried and a red light flashes very fast to signify the fault. And leaves roughly 2 inches of water in the bottom.

I have run it with waste pipe just into a bowl on the floor to see if it was a waste issue. Problem persists. The drain pump runs but just not for long enough it would seem.

I have put a new drain pump in it and the fault persists.

I took out the one way valve flap to see if made any difference in waste just past drain pump still no difference.

The waste pipe is clear all the way from drain pump for definite.

I checked the pressure switch and that is working and switching between poles ok which controls the pump. But not sure where other end of the tube is joined up to.

Tube to pressure switch looks fine.

http://www.reliablepartsinc.com/danb...RTS%20LIST.pdf

Here's a link to part list. I'm at a loss. Could it be control panel?

I even tried plugging into a different circuit to the same as refrigerator (which it's next to) in case of volt drop from that pulling too much load.

I'm not massively in to rinsing plates etc before I put in, but the dishwasher never gets blocked filter basket and still looks like new. There was no waste what so ever in the waste pipe.

Any suggestions gratefully received.

Thanks in advance for reading this

David