Boyu cannister filter

Hi there
I hope this is the appropriate place to enquire about the following issue.

I have a boyu canister filter that a friend gave me and said doesnt work, I opened it up and found that the rotor was clogged with gunk, I cleaned it out and plugged everything in, when I put it in it started to pump and then sparks came out of the switch that controls the uv light, so again I took it all apart, took out the uv light and silicone the whole uv compartment closed, I also plugged the switch out and used insulation tape on the clips that were connected to the switch, before I plug it in and shock to death I just wanted to find out if any1 has experience with an issue like this?

Kind regards