I too have a bricked unit, and the retailer will not be able to replace it for 1-2 weeks.
I'm very keen to find out how to un-brick it.
Here is my message to Kobo Customer Service from yesterday:
Purchased Kobo from Angus & Robertson in Australia, unit worked fine. Connected to pc(using Ubuntu Linux), opened Kobo Desktop, was prompted for an update and followed the instructions. At step 8 all had went exactly as the update was meant to, unplugged usb and waited for software installion to finish - it never did. The "one moment please" screen stayed on indefinitely and never finished (reader only had the pre-installed free books on it).
Reader is now not recognised by pc on usb, cannot get back to update mode, all buttons unresponsive, the 'paper clip' reset reboots - but only to the seven bar progress indicator where it stays -- basically 'bricked'. Contacted phone support, with no success. Advised to return the device to bookshop for replacement. (Have to wait a couple of days for new stock)
On Mobileread forums
https://www.mobileread.com/forums/showthread.php?t=89833 SameerH from Kobo was looking into providing the software image from the SD Update card as a method to help those with failed updates. Users could then copy the software on to their own SD card. Could this please be made available quickly ??
It would save me (and many others) from having to return the device, and it seems a more reliable method. Formatting an SD to ext2/3/4 etc is no problem.
Since then I've been able to get into Update Mode and retry - but still stalls at step 8 and will not fully load when rebooted.
Are there any secrets to help un-brick the device? Can anyone share some info?