so I bought this led grow panel at the 2nd hand shop in town for 15 bucks. I found the same one on ebay for 80 bucks so I think its a expensive light. I took it apart and discovered what appears to be a large diode. This diode is on the red wire feeding the panel 12volts. what does this diode do and why is it getting so hot? how do I know if this thing is safe for 24 hour usage?