HELP! Baumatic BI631 UNRESPONSIVE

Okay, so I like to think I take quite good care of my dishwasher. I clean it regularly and rinse out the drain every second wash. But a few weeks ago, I started getting the Eco and Intensive flashing error, and the washing machine was making a terrifying grinding noise when it was turned on. I poured drain cleaner down and left it for a few days. That took care of the grinding, must have been clogged. After research I found out the flashing error was the flood safety. So after much heaving, I managed to get the black panels off the front of the dishwasher off.
I should clarify, I didn’t install this dishwasher, I am a tenant and this was built in to the kitchen when I moved in. But as tenant, I am 100{e5d1b7155a01ef1f3b9c9968eaba33524ee81600d00d4be2b4d93ac2e58cec2d} liable for looking after it. The black panels were almost impossible to get off! Took me hours of prying with a screwdriver!
Mopped up the inside of the machine, some water but not pure loads. The last time I pulled out the towel there was some nasty gunk on it. Boyfriend says it was rust water, but now I’m not sure.

The flashing error is GONE. I thought it was fixed and was SO happy. But now the dishwasher won’t do ANYTHING. It’ll turn on, the power comes on… But that’s it. It won’t let me pick a program and it just sits there silent. Could I have disconnected something while I was mopping? I can’t properly see in the bottom of the machine, so I was just kind of feeling around. I haven’t put the black plates back on the front as they were so hard to get off. Do I have to put them back on to get it to work?

Please, help!