Nubs
The Pandora has 2 analogue nubs, which were custom designed.
Early Nub Problems
The nubs on some of the first units suffered from a myriad of issues. The issues include bad traces, bad resistance in the joystick, looseness, grittiness, nubs not centering, and nubs sticking in one direction.[1] Much of this was caused by the nub manufacturer not having strict enough tolerances[2] and not 'bare board' testing the PCBs used in the manufacture. Probably the most serious problem is that the nubs can break mechanically, resulting in a nub which cannot centre itself. This causes drifting while in-game, rendering the nub completely unusable.
Because of these problems, a few "one nub" units were made available to people who wished to accept one and skip the queue. The faulty nub is not covered under warranty for these units. Reports[3] suggest that many of these were reasonably functional, and problems relate to either the calibration process or dirt inside the nub. There is a risk that these nubs might fail with extended use. Soon after the first units were shipped, 100% testing was arranged for the nubs by the supplier and OpenPandora Ltd. (This applies to units shipped after July 27,2010 which are expected to all start with known good nubs)
Nub Calibration
Push them up, down, left, right to the edge, then let go of them so they spring back by themselves. Ie push up, as far as it will go, then let go (it must spring back). Do that for each direction. Then do some circles. That should set them up. If you don't do this they can go wrong during that session until reset.[4]
Nub Disassembly
This is a fairly tricky process, and will almost certainly void your warranty.
You need[5]:
- High quality soldering iron
- Solder Wick
- Shim Blade (Edsyn RB641)
- Isopropyl Alcohol cleaner
- Size 0.00 cross-head screwdriver
Removing the nubs from the PCB is difficult. They are mounted using cut-off plated through holes butted onto pads (fairly standard SMT technology). Just using solder wick will not be sufficient, and if you are not extremely careful, you will rip the pads off the nub or the board.
This shows the under side of the nub, which has a small PCB screwed on, and 2 locating pins.
Full sized versions of these photos can be found here. Original pics from Claude
Top left is the micro-joystick which serves as both a spring and the sensing element. when re-assembling this must fit perfectly into the plastic, and be perfectly clean.
--Tsh 13:08, 17 June 2010 (MEST)
