Lighting equipment is incredibly expensive, so when your lights stop working, it can feel like you just flushed thousands of dollars down the toilet. Of course, you could send your broken stuff off to be repaired by professionals, or you could learn how to fix it yourself all while saving some money in the process. In this step-by-step tutorial, Casey Schmidt, DP, grip, and owner of Northwest Grip in Seattle, shows you how to diagnose and repair electrical issues that are common with older tungsten lights. Check it out below:
Even though Schmidt's video zeros in on the repair of a faulty SJO cable in an ARRI 650, which may not be the issue with your particular unit, he also offers a lot of great advice on how to repair tungsten fresnels in general, as well as specific insight about their construction and electrical layout. So, if you're familiar with working with electrical, this tutorial will definitely give you a lot of the information you'll need to work on these types of lighting units.
However, if you don't have any electrical repair experience, I'd say proceed with caution. You don't want to end up harming yourself, others, or your gear. It's always a risk attempting to fix electrical issues as a non-professional (it's a risk even as a pro) with little to no experience, so make sure that you unplug your lighting unit before you start tinkering with it and take all safety precautions to avoid getting lit up like a Christmas tree.
If in doubt, send it out.
Source: Casey Schmidt