I got this knife as a gift several years ago, I don't really use it a whole lot but I do like to take it camping and such. However, on a camping trip a year or so ago, it got stuck open.
There is some little wire loop looking thing that seems to pop out of wherever it's supposed to be and blocks the thumb unlocker from working. I can take a tiny screwdriver or Allen wrench and poke around in there and pop the thing back into place, and then it works and closes just fine. And it'll be fine for a few times, opens and closes correctly, but after a handful of times that piece inevitably pops back out again and locks it open.
I've tried to use a tiny torx bit to remove the sides to see if I can figure out what's going on, but the screws just spin. The big screw at the hinge unscrews as expected but all the little ones all act like they're stripped.
What else can I do? Is there some trick to removing the sides? Any help would be appreciated.
Here's what it looks like opened correctly with the little piece still wherever it's supposed to be:
And when the piece pops out and gets stuck:
Somewhat useful red circle if you couldn't see the problem:
This is, alas, a cheap knife. Now it's doing cheap knife things. I mirror @cetan@piefeed.world's prediction that the part getting out of place and causing you trouble is the spring for this knife's spring assist mechanism. It's supposed to have a hook bent into it that rides in a hole in the blade's heel. The hook may have snapped off, or your main pivot screw may have backed out to the extent that there's now too much of a gap to prevent the spring from working its way out of place. Based on the amount of gap I can see I theorize it's the latter.
You'll probably find something rather like this lurking beneath one of the scales:
How that goes in is the hook on the end goes in the hole in the blade, and the wiggly part of the spring rests flat inside the pocket carved out for it on the back side of the handle scale. There will be one (or most likely, two) positions in the blade's rotation where the spring is completely slack and won't be under tension against either the edges of its pocket or the barrel of the pivot screw, and keeping the blade there when you reassemble the knife will make your life a lot easier.
It's unlikely any screw in this knife has an anti-rotation flat on it, especially the main pivot screw, so you're undoubtedly going to need to stick a screwdriver in each side to get any of them undone. Cheap screws are likely to strip when met with cheap screwdrivers, or at least screwdriver tips. I prefer Wiha screwdriver bits since they seem to hold up the longest. The body screws are probably threadlockered as well, and you can encourage them to let go by pressing the tip of a hot soldering iron against them for thirty seconds or so. I'd advise against bringing a heat gun or torch anywhere near it.
T6 Torx and T8 Torx are the two sizes you'll need most often for taking apart knives. You can buy these online individually for a buck or two a piece of you don't want to shell out for a full set.
I'd categorize this as a learning experience: This is an inexpensive knife that's not exactly manufactured to a high degree of quality or care. But the way it comes apart and goes together is indicative of most modern folders which includes better, higher quality knives you might own in the future. If you ever have to delve into one of those, the skills and construction methods you learned from this one will be useful.
Thank you! I sorta figured as much about it being a "cheap knife". That's why I'm not too attached to it and am basically at the end of my patience for trying to fix it. If I can get it, great, if not, oh well.
I'll give the soldering iron trick a shot and see if that lets me open up the body screws. But if that still fails or more screws strip out, I'm just gonna drop the thing in my door pocket and call it a dedicated car emergency tool and shop for a replacement. It does technically open, at least once, and all the little extras are still useful for that purpose.