This may fix your A-Stick...

[hak...@gmail.com]

For those that have had problems with their A-Stick, I've recently had
a chance to get a feel for what's going on with it...though your
problem may not be solved by what I write here, it's worth checking
out.

First off, don't worry about getting the calibration program. I think
I suggested that before but it did nothing for me and there's a
calibration built into the firmware as of 3.97 I believe. To access
this calibration, on the XMB, go to SETTINGS -> SYSTEM -> SYSTEM
INFORMATION. On this screen start doing circles on your A-Stick.
This should recalibrate the stick and keep it from moving constantly
in whatever direction it was moving in.

If this does not work, then more than likely, there's a screw too
loose or too tight within your PSP. To give this a test, play a game
or load a homebrew that gives you accurate feedback of how far you
push the stick. In that program or game, mash the face of the psp
near the D-Pad. If you see that this affects your analog movement
(don't worry about actually touching the dpad OR the stick) you have a
screw problem.

Unscrew the face off the PSP and back off the screws holding the
analog stick assembly about a quarter turn then put your psp face back
on and make sure all the screws are tight, especially the ones on the
same side as the dpad and stick. If this makes things WORSE, take the
face off and tighten the analog assembly screws and try again. I know
it's a pain the ass, but it's worth it to not have the cursor jump
around on pspseq.

Eventually, you'll find the A-Stick behaving again. Be sure, once you
get that 'sweet spot' once the face is on to mash around the A-Stick
or Dpad on the face of the unit to make sure that it doesn't make the
A-Stick register pressure. If it doesn't register, then you're as
close to perfect as you can get.

Be advised, I've only done this on the PSP Phat. I cannot verify that
this will do anything to help or harm your a-stick on the slim or 3000
models.