FIRE!

So... Currently I'm trying to get the smell of smoke to clear the basement, but here's what happened as far as I played a role:

Starting a little back:
I was having issues with my SD2's y-axis. The motor would be stop-go-stop-go-etc as it spanned the move (if you watch Family Guy, imagine Peter Griffin's laugh, but the noise generated by movement of the motor). The other axes were good, so I wanted to isolate the problem. I switched the x motor to the y plug on the board and it had the same issue, so I figure it has to be the stepper chip rather than the motor itself. Online research says occasionally, SD's ship with stepper chips that will just fail. Luckily, I have a Prusa i3 which is currently out of commission as I fix a few things on it, so I say "ok I'll take the stepper chips out of there". All the pins are the same. I assume it's the same chip just maybe a different manufacturer. I put in the one chip, turn it on, adjust the voltage, and the y axis now works. Except now that same issue is taking place in the x axis (yes, I rewired everything back right after the earlier testing step). Replace that stepper chip with an i3 one. X and Y good. Z no good. Replace that one. Extruder, swapped chip as well.. Now all stepper chips are from the Prusa. All axes work.
Before the Y axis went out, I had an issue once or twice where the power would just go out on the printer from the power supply. After replacing stepper chips, I started a print and the power kept going out and the USB kept getting disabled by my computer because it's drawing too much power. I look this up online. An upgraded power supply is apparently a very common upgrade for the SD because apparently the stock one is underpowered. Which upgrade do they recommend? The same one I have for the Prusa (same voltage, 30A vs 11 or 12A). Boom. Swap it in. Turn it on. Look at my computer. Look back at the printer. *Do the stepper chips usually glow orange?* Flames are coming out of the Z-axis stepper chip. Shut it all down, air the room out, wait for it to cool and examine the damage: it seems the fire was limited to underneath the heatsink on the stepper chip. Upon taking the heatsink off it looks to have been on one side of it. No burns are immediately apparent on other chips or the main board.

Anyways. Where do I go from here? Should I replace the stepper chip and power it back on? Using what power supply? Using what stepper chip? Should I contact Solidoodle?