What I did
When the event happened I was very shocked and momentarily paralyzed because it was so violent. Fortunately a thorough review of the emergency checklist memory items paid off as I immediately turned off the master and alternator switches. At that point my brain froze and I sat stunned in the seat for probably 10 seconds until the brain kicked in. I started by verbalizing out load aviate, communicate, navigate.
So I asked myself what do I need to attain and maintain immediate safe aircraft operation ( Aviate). So first off I needed to determine I was not on fire. I Leveled the wings reduced MP to low cruise quickly checked the aircraft was trimmed for more or less straight and level, then got out the fire extinguisher from under my seat turned off the cabin vent controls and cautiously leaned over to the right side CB panel an ran my hand near it. Definitely warm but nothing burning, the slight electrical smoke haze was dissipating and there were no sounds indicating arcing. So I pulled the emergency check list and ran through it to make sure I had not missed anything
Then I thought where am I going ( Navigate).. The departure flight path was basically over the airport so I established a gentle bank to circle where I was so I did not get too far from my last known position. Clearly I was going to need some instruments and radios to get back on the ground so I pulled all the remaining circuit breakers and then held my breath and turned on the battery master. After a minute when nothing bad happened, I reset the CB for the AI. It came to life and a few gentle turns and pitches proved its operation. I then tried the HSI CB which popped as soon as I pushed it in. I then tried the No 2 Nav which had a dedicated stand alone head and it came to life and idented the local VOR which gave me a radial that made sense from where I though I was. I then tried the turn and bank CB but it popped as soon as I pushed it in. At that point I decided I was not going to push my luck and decided the last thing I would try to energize was a comm. The No 1 Comm CB stayed in and I head voices on the terminal frequency.
At that point I gave a think about what I wanted to do so I could tell terminal the plan. ( Communicate) . The good news is the ILS was on runway 27 so no turning error on the mag compass if I did not accelerate /de-accelerate. I decided I would get terminal to vector me to intercept the ILS from below at 8000 ft ( 1000 ft above the tops) This would allow me to get the gear down with the emergency system and get stable while still VMC. So I got on the radio declared the emergency told then what radial I was on to help the prime target ID and got no gyro vectors. The ILS was uneventful and the calm air certainly helped as I could use the mag compass for heading info. ! broke out at about 500 ft and landed
It turned out that there was some electrical "repair" carried out by the last owner that resulted in a main bus bar being put back without any fasteners to hold it in place. During a ATC commanded turn on the departure it fell off and landed flat on an aircraft frame which caused a massive short. Our engineer figure there was so much juice flying through the airframe it took out a lot of other services. There was a lot of damage and the cockpit ended up being almost entirely rewired at great expense, The good news is several other really scary electrical issues where also found and corrected.
The bottom line is this is the poster child for "use your superior judgement to avoid situations requiring the use of your superior skills " . The fact that I took off that day reflected very poor decision making on my part but I decided to write about this because the use of the trite "aviate, navigate,communicate" mantra was a significant help to me in prioritizing my actions in the very difficult situation I was presented with and so If you are suddenly confronted with a bad situation and are momentarily unsure of what to do verbalizing those 3 words may help.