I tried to hook up external power to an RGB LED strip that I had running off a Spark Core to make it brighter and I think I fried my board. Now the onboard LED won’t turn on and it just gets warm.
Any ideas on a resolution other than buying a new one? It was a pretty dumb thing to do in retrospect…
Could you tell us the exact set-up, and the things you’ve done? If you’re lucky, you’ve ‘only’ killed the voltage regulator and perhaps some pins, and there might be a way to salvage some.
Unfortunately, this is comparable to trying to un-crash a car. You might be able to fix some of the issues, but you’re likely to have some permanent damage.
Anyhow, let us know, perhaps it can still be (partially) saved.
No worries, I figured as much 
I should have double checked the voltage on the external power supplies.