Yesterday, my Prusa made a loud beep and turned off and never on again

I didnt know what happened, but I knew that I had some problems in the last weeks which I thought I fixed. The rods where to dusty which resulted in the X-Axis skipping. I cleaned thhe rodes and sprayed some Teflon grease on thm, as usual. Maybe something got into the electronics box and the grease isnt as non-conductive as I...