Recovery Mode: Top Button and Volume Button Up.
Run WebOS Doctor and follow instructions.
Each Stage of WebOS Doctor:
1. WebOS Doctor begins
2. At 3%, a ramdisk is transferred to the phone, and the phone is rebooted
3. At 4%, the screen changes to the HP logo
4. At 9%, the screen changes to a big arrow pointing down to an integrated circuit
5. Novaterm access is available from 12% onwards
6. The progress bar advances by 2% increments every 20 seconds or so
7. If it gets stuck at 52% for more than 30 seconds, it's not going to progress further 8. and you will need to try again.
9. Around 54% the filesystems are being partitioned
10.Around 64% the modem firmware is being reflashed
11. Around 72% the carrier apps are being installed
12. Around 82% the ROM is being verified
Doctor disconnects at 8% Fix:
If the webOS Doctor continually disconnects at 8%, then you probably have a corrupted USB drive. This is how you can fix that (note that this will completely and utterly destroy all data on the USB drive).
If you are reading this following an interrupted webOS Doctor, you might want to try to extract the installer uImage from the version that was there before the interrupted procedure. For example if you were upgrading from webOS 2.0.0 to webOS 2.1.0, you might want to try the uImage from the 2.0.0 webOS Doctor jar.
First put the device into recovery mode, then memboot the device using the installer uImage (extracted from your webOS Doctor jar):
novacom boot mem:// < nova-installer-image-castle.uImage
After it boots, run novaterm:
novaterm
Once connected to the device, type:
lvm.static vgscan --ignorelockingfailure
lvm.static vgchange -ay --ignorelockingfailure
then type:
mkdosfs -f 1 -s 64 /dev/store/media
Once that completes, put the device back into recovery mode and run the webOS Doctor.
12% Fix:
1. Run Novaterm while on 12%.
2. Type this:
dosfsck -r /dev/mapper/store-media
3. Choose "Yes"
4. Restart devise and run WebOS Doctor again.