No more access to USB Stick

[Donzar]

The story in short:
No more access to 2GB Apacer USB Stick (Win2000 SP4 / WinXp SP2 several PC's)
First analasys with ZAR unregistered successful - Few Files restored
Changed computer
Computer recognized Stick as n e w Hardware (now the real problem starts)
The stick has been renamed to USB DISK 28X
Registered ZAR ;-))
ZAR can see the stick but shows now - Capacity 0 B
ZAR - There seems to be no volumes
Scan for missing partitions - Invalid partition table ....
Define volume manually - There was only one volume on disk
Scan for missing partitions - no action
Define volume manually - Start location 0 / 32 / 64 / 128 /254 sectors
Volume size 2048 / 1024 / 512 MB
Error: Volume starting location out of the physical disk

95% of the stick is on a backup - so it's not a real problem if I can't get the rest. But I would like to understand what happened - so I can do better next time. (Since I have now a registered version of ZAR ;-) )

Thanks
Don

[Alexey V. Gubin]

If USB stick indicates 0 bytes in size, this typically means a hardware failure of the stick and/or of the USB port.

Of the failure cause we've seen

ZAR misconfiguration - if you have it set to read logical drives instead of physical and the data structures providing logical drive information are damaged.
It just run out of lifetime and died.
Electrostatic discharge shock.
Manufacturing defect.
Now this one is interesting - the USB port attachment to the motherboard is messed up (the connector is attached upside down, or pins are misaligned - off-by-one). Such a port may kill whatever USB stick is inserted into it, especially if the connector is installed in such a way that power gets to the data line. Albeit rare, such things happen.
Typically, there is not much chance to get it back to work.
Your options are

Try both "Disk access using physical devices" and "Disk access using logical drives" settings. To change the setting, on the first screen click "Advanced configuration". In there, the mode switch is at the top of "Disks and partitions" panel.
Try if it works in the different USB port.
Try if it works on the different computer.
If the above does not help, try formatting the stick in Windows. Unlikely it will work but still worth a shot.
If possible, get the manufacturer's diagnostic/format software from the stick manufacturer. This may or may not be available depending on the manufacturer. Try this software to see if it can resolve the zero-bytes-capacity problem while not destroying the data on the stick.