OK Bravo,
For you and whoever else needs it:
Remembering what everyone else said, I'm trusting you've looked for all the simple stuff first, i.e. in software, tried alternate USB ports, recallibrated in both Windows and AH and so forth.
I have now received my Microsoft Sidewinder Force Feedback 2 Joystick. Mine is part number X08-58736. If your number differs don't worry. If the exterior is similar there should be little or no difference. I have dismantled it and made some photos for you as promised.
From what you reported I suggested it might be a mechanical problem. This we can certainly check. You should have no trouble dismantling it enough to check for such damage. It really is very a simple process. Don't panic!
I imagine I am obliged to say something like I am not liable for any injury and it's at your own risk blah blah blah. But I'm confident you will survive!
It's probably easier to work with the stick inverted on your lap, with the handle hanging down between your legs.
Firstly, on the underside of the stick's base, there are three very obvious screws nearer to the middle. These potentially present the only problem. They are not anti-tamper screws or Torq-sets or anything weird like that, they are modified Phillips screws to make them 'tamper discouraging' shall we say.
I found that a Tamiya Philips #2 screwdriver fitted perfectly. Any Phillips screwdriver OF THE RIGHT SIZE will fit too, do not be tempted to make do with an incorrectly fitting screwdriver, because if you damage these screw heads it is game over. If you put the driver in the screw and it is a positive fit and doesn't wobble etc, then you've probably found the correct driver.
The screw heads are of a modified pattern to make it harder to unscrew them. The trick is to use much more downwards pressure onto the screw than turning pressure. I found they were not very tight, once they clicked loose they were easily removed. Set these 3 screws aside safely.
Next you must pry off the 8 rubber disk feet that are found near the edge of the baseplate. They are self adhesive. If you get something reasonably sharp that you can force completely under the edge, you can simply lever them off. Once you've done one you'll understand it. Lay these carefully aside, adhesive side up and try not to touch that surface. They can simply be reattached afterwards.
Under each rubber foot is a normal Phillips screw. Remove each one and set them aside. These screws are all exactly the same length, no need to make note of where they came from.
Once this is done, the bottom plate easily comes away. Revealing a gimbal, two circuit boards and two electric motors with a small black gearset.
The dark green circuit board with CAUTION and PRIMARY and SECONDARY printed on it is the power circuit and should be loose. If you jiggle the black power lead socket it should come out. Grip the circuit board by the edges and just fold it out of the way. It's unlikely, but there is a tiny possibility that there is some residual charge in the capacitors (the silver cans with the black sleeves on them). It's generally good practice to avoid touching the electrical parts if possible, but don't get stressed over it, I gave it a proper wrangling with no ill-effects (although I did seem to lose an hour today and now my hair is all sticking up).
Lifting this circuit out of the way will let you look at one of the gearsets. Start here looking for damage: gnarled or missing teeth, foreign objects, something loose etc. The gears should turn the motors smoothly when you move the stick. There should be no clunking noises or binding etc.
If this gearset is good, remove the two screws which hold the light green circuit in place. They are at either end of the 'Microsoft' text. Lift the circuit board as needed so you can inspect the gears, handling it as carefully as possible. Take extra care not to stress the wires that go into the tiny plugs. If you like you can unplug these, grip the plugs on the plastic edge with some pliers with serrated jaws (otherwise they'll just slip off) and pull gently. On no account try to unplug them by pulling on the wires. Each connector is unique, you cannot reconnect them wrongly.
This gear set looks like this:-
Again look for the same damage, move your stick around and inspect the gearset.
If you find no problem here then you must inspect the gimbal. This is the part in the centre of the stick which translates your sticks movement into the two channels used for Ailerons and Elevators in game (the rudder pot is in the handle of the stick and has no FF).
The gimbal looks complex but it's really not, just check everything moves properly with no binding (sticking) or clunking. Check that the wear is reasonable with nothing slopping around.
If that's all alright you need to look at your motors. Move the stick and listen to the cans for odd noises. It is normal for it to feel a little notchey (softly notchey), it is just the coils moving past the magnets. Give the motors a sniff (bear with me here, lol) if one of them smells burnt this is significant.
I went a little further with my disassembly than you probably should and completely removed the gimbal from the stick's housing. Hopefully these pictures help you look for anything wrong. This is basically how one gear and motor set are attached to the end of your stick:
If you do find something broken or loose, please make a picture and upload it and I should be able to give you a reasonable solution, within reason. This might include a suggestion to replace parts!
If everything checks out OK then it is not a mechanical problem. That's also useful information. You probably then have a worn out potentiometer, a fault in the digital circuit or a problem with one of the motors that you can't see etc.
That probably leaves you with limitted options to be honest, since you said you're not so good with electronics. Electronic diagnostics is a bit more involved than the mechanical side. As I mentioned earlier if you still have your other broken stick you can always substitute parts block for block, without too much understanding of what they do. As I say, follow the instructions for disassembly first and let's see what you find.
Here I'd love to say reassembly is the reversal of disassembly, as I always read in manuals ha ha. It's actually pretty true, but there are a few provisos. When putting all the boards back in place, carefully reroute the wires so they can't get snagged in the gears etc. There are little tabs provided in the case.
When refitting these kind of self-tapping screws back into plastic, I find a good trick is to position the screws vertically, turn the screwdriver slowly backwards until you hear a click, then turn the screws carefully in (clockwise). Do not over tighten them. I think they need about two and a half full turns of the screwdriver each but it will be pretty obvious when they've had enough. Just a little more than finger tight is sufficient.
The final picture shows it reassembled plus the tools I used. I tested it straight after and it worked fine.
I hope you can follow the guide. It does look very complicated but it's just long winded, I've tried to cover everything and assumed you didn't know anything.
Hope you find something that is easily fixed, good luck!