Please help! Hotpoint Aquarius FDL570 not working?

My Hotpoint dishwasher is about 4 year old now and to date we have had no issues with it. This good run is now over it seems!

I start the cycle as normal and it begins, within say 20 seconds it stops with all lights flashing constantly.

I have read a few posts suggesting to tip it back to release the water. I have tried and repeated this process a few times and some water did come out although the issue remained.

I have also removed and thoroughly cleaned the internal parts hoping this might be the cause but this has not made any difference either.

I called Hotpoint to ask what the lights flashing in this way means as I could not find anything in the manual. They claimed it must be a faulty circuit board and that they cannot offer any advice to fix it over the phone but can call someone out to the sum of £110 with no guarantee of fixing it. The alternative to this is their 'repair or replace' service which will cost £185 for 1 year but at least it will result in a machine that works.

Before I go down this route with Hotpoint direct can anyone offer any advice as to what could be the problem and how I might fix it?

Many thanks in advance.
Sam