After having my DSLR Nikon for seven years, it finally stopped working in the midst of shooting. At the moment, I knew it wasn't just the battery since its light wasn't flashing and the battery still had some juice. I was afraid the motherboard fried.
My hunch was fairly accurate. I took it to Tucson Camera Repair, who inspected it for a $45 fee. I got a call a few days later, informing me that the DC/DC printed circuit board (PCB) assembly needed to be replaced and the main PCB needed to be fixed. The former part was back-ordered, so it took three weeks to arrive.
I never thought I was as attached to my DSLR as I am to my older analog cameras. Alas, after taking it around the world and country over the years, I missed it dearly. I'm relieved to have my camera back. While I've made minor repairs or adjustments to old cameras, I feel rather helpless with circuitry. I'm also glad it wasn't a more costly part that needed replacing; the total service, including a sensor cleaning, cost about $200.