Depends.
My main desktop has a hard drive connection glitch frequently or some odd reason. I fix it myself- It's really simple.
My Nintendo 3DS has this creepy glitch to say the least. Randomly, it crashes after 20 seconds when wireless is on, saying "An error has occured. Please press the POWER button and says go to support.nintendo.com for assistance." After the updates on 15th May, I don't think I saw much of them, really. In any case, what was needed to fix it was a simple free-fall from about three feet on a soft surface. It fixes it until it randomly wants to glitch up my 3DS again. I plan on having it checked though, I think the problem might be hardware. I will do that if it glitches up again. But, it didn't in a while, so as long as it's working, meh. But when I sent it to repair, they just mentioned it's a software quirk... Ngh.
I don't touch my other devices, these are the only two I'm familiar with repairing.