IC heating up

[Marbles]

Hi guys,

Had a RC Booster that wasn't working anymore. Checked it and had no activity past the IC. Touched the IC and it was sizzling hot. Couldn't touch it for longer than a few seconds. Thought I might have a bridge somewhere, but couldnt find anything. It was hot directly after turningit on.
So I just replaced it with a new one and it seemed to be fine.

Put the powersupply in, and turned it on for over an hour while doing other stuff.

When I returned it was fine. Still worked, and the IC wasn't hot.

Could this just be a faulty unit? I gave it to a friend and I'm kind of scared to give it back now haha. Is it possible that a faulty IC burns up? Or is it something in my build that could be the cause of this happening again?

[motterpaul]

I am guessing that at some point while the first IC was plugged in you somehow sent +9 to a pin that does not want to see that, and you burnt up the IC (it happens often with ICL7660s). Sometimes the ones that get hot will work after the power is sorted out, but sometimes they get burned out.

Then - at some point that bad wiring was fixed, and you put in the new IC; which was never exposed to whatever burned up the first one, so it should be fine.

[Marbles]

Thanks for you reply!

So it's possible that because it burned out, it heated up everytime? Cause it heated up, I took it out and put in the other without changing anything.

Maybe I have made a mistake in my build.. I remember not soldering a leg of the IC socket initially and the unit not working. If I messed it up then, it means it has been working for 2 months before it failed, is that possible? I have no other explanation or thing I changed between changing them...

[Ed Nice]

It might be worth checking voltages just to be sure. If they are ballpark, it means the build is ok and could well have been a dodgy IC or your missing joint? :)  

[Marbles]

Thanks a lot! It seemed to be fine... I knifed a bit for good measure, and eventhough I used 'potcondoms'  i put a gaffertape covered piece of cardboard between the pots and board... Fingers crossed :)