Check the valves on the system to see if they are causing the leak. If they are, try to tighten the nuts or, if that doesn't work, replace the washers. Don't try to repair a valve yourself if it appears to be broken.
Check the solar panel's pipes for water leaks. If you find one, disconnect all of the wires and shut off the water. Drill a hole at the site of the leak and patch it with epoxy, then allow it to harden.
Isolate any solar panel that bursts due to freezing or high pressure by turing it off. Call a technician to fix the problem.
Call a technician for complicated repairs that you can't figure out what the problem is, as you may lack the expertise required and may cause further damage to the system. A qualified technician will also have access to the right parts.