Did I fry my mobo?

recently my external hard drive was having problems booting up. It booted just fine except for occasionally it just didn't and I had to either switched off or switch and switch it on again or unplug it and plug it back in and then it would come whirring to life.
then one day it just didn't. I thought that it might be the external hard drive enclosure power system so I took the hard drive out of the enclosure and put it into my tower. when I first booted up it worked just fineand I was able to get information off of it. Then suddenly It told me the hard drive is unavailable as if it wasn't powered on. So I did what I did when that happened on the external Drive. I unplugged it and plugged it back in. On the external drive all that did was cause the computer to forget it and discover it again. However I did not anticipate that unplugging it using the internal power source would cause any difficulties. What actually happened was there was a spark and the entire computer shut down. when I tried to boot it up again the power button is completely unresponsive. I even tried turning it off at the back, turning it back on, and try again and no luck. Even if I completely disconnect the hard drive I was working with and try again, no luck. Not even a splash screen, no beep, no fans, nothing. did I short the system out and by doing so foolishly managed to fry my motherboard? D: what do I do?

Does the power supply run when you turn the system on?

Does the outlet the computer is plugged into power anything else and if so does it work?

Its possible you did fry you're mobo but its also possible you tripped a safety feature that resulted in the system just shutting down

Actually, I discovered that it is not so grim. When I removed the drive and switched the computer off at the back, waited a few seconds and switched it on again, it boots up fine.

But if I plug the drive back in, it doesn't boot at all. So I thought maybe it has a short and is overloading the PSU. I tried fitting it into a different external frame, and even when I powered that up, the drive doesn't spin up.

So I'm guessing I fried the drive? Is there any way to retrieve the info from it?

In that case it sounds more like you fried the drive.

Unless a computer can see the drive the odds of you being able to do data recovery are slim. Yes I'm fairly sure the data could be recovered but would require more specialize setup then what you have and would cost a few hundred to a couple thousand dollars to have a professional data recovery done on the drive.