I screwed up today when testing a breadboard with 3 TL074's and a 5532. I accidentally plugged in one of my supplies (I'm not sure if it was the +15V or the -15V supply) with the power strip on, and I didn't plug the second one in soon enough and I may have fried the chips...The circuit no longer works, which leads me to believe I've fried them, but I have two questions...
How can I tell for sure if they are damaged? Is there a resistance test or something I can perform to check?
More importantly, why are they sensitive to having one supply plugged in before the other? What kills them when this happens?
Is there a resistance test or something I can perform to check?
No.
But you can look at the current they draw and compare this with a non suspect one.
why are they sensitive to having one supply plugged in before the other? What kills them when this happens?
Over current kills them. The circuits latch up, that is they do not act as transistors but conducting diodes. Some devices like OLEDs have three or four supplies that not only must be brought up in the right order but also within a strict timing.
Save your self a lot of grief and simply change them out, You DID use sockets didn't you?.
The parts are common and you should have Extra's... You did buy a spare or two... Just in case...
You're not the first to make that mistake. First fix your power connector by changing it to a polarized type of plug or likely you'll do it again.
You have just joined Murphy's club... Oh I'll NEVER make that 'mistake'...
So I really don't have to take precautions to prevent damage in the case that I DO make that mistake.
I stopped By to see Murphy once and met his Widow instead. She said to me yes and there he lies, poor old sod... Ever the Optimist, Even when he Knew better.