NOT SURE IF THIS THREAD IS IN RIGHT AREA
So I bought this IR receiver from RadioShack, and it worked fine with the Arduino Uno until I accidentally reversed the GND and the Vs. It then got really hot and burned my finger :~ and it no longer worked. I have read other articles, and most of them mention smoke, but mine just had the fresh-out-of-the-oven electronics smell and no smoke. So is it OR the Uno fried, or does it just need some cool-off time?
More than likely you fried the IR instead of the arduino.
Have you tried testing the arduino with something else (besides the IR senser) to see if the arduino still works? How much voltage were you using to power the IR when you accidently reversed the ground/vs?
Just because you didn't see smoke doesn't mean the IR wasn't fried. 
That is why it is called magic smoke - it is sometimes invisible
partsofme:
More than likely you fried the IR instead of the arduino.Have you tried testing the arduino with something else (besides the IR senser) to see if the arduino still works? How much voltage were you using to power the IR when you accidently reversed the ground/vs?
Just because you didn't see smoke doesn't mean the IR wasn't fried.
I was using 5v. The Arduino isn't fried, and the IR isn't working anymore, so I guess the IR is fried.
One of the reasons why I always buy more than one of a given component:
If I suspect that it's dead, I have something to compare with. (And it is not unseen, that I have set the magic smoke free)
And the IR receivers have different pinouts!
LadyAda has a way to test your receiver here: