Trouble-shooting is an art form. Learn from your mistakes and try not to make the same ones again. I know I've made plenty myself. I've messed up worm gear bearings, burned up a few boards. And I don't even want to try and count how many meters and cell phones I've drop down the shaft.

Ha don't worry about it mate. As JKH says, we all make mistakes or miss an obvious fault, and if someone says otherwise they are lying. Just learn from your mistakes/errors and as you have done admit to it. All of this makes a better person but importantly a better mechanic.

It is better that he fixed this one -- cuz you will never forget the experience. If you 'd have fixed it, you might forget next time. Keep head up.

ONe time I blew up a hard start kit trying to get an air conditioner to run (AC my first love, elevators my second love). They are used to start a locked compressor == bad start winding, whatever. I've done it many times before and they work great. I put it on pushed in the contactor and BOOM! Acid and stuff everywhere. Then the wiring caught fire and I ran.

Also burnt up 3 boards in an MCE Legacy control....jumped something to ground (done it many times before) and put it on the 2 bus terminal strip. Ooops. Looking for fire extinguisher. Ordered boards, had it running the next day!