Why did my lumia 520 keep at the spinning cogs hours at a stretch till the battery drained?

[Godson Arun Kumar]

My lumia 520 had huge trouble with this latest preview version. The cogs kept spinning with no sign of the worm even emerging. I got up the next morning to see my phone switched off. I Connected the charger and just the battery icon kept flashing. Hitting the soft reset brought back the spinning cogs. Hoping that it was bricked, I started downloading the recovery tool, when all of a sudden the worm at the spinning cog emerged and met the end in about 5 minutes. Tada...my phone was back. Any way why did this **** happen?

 

[Torcher Death]

Its always a good idea to plug in your phone while updating, that way battery drain & switch off can be avoided.

 

[Godson Arun Kumar]

Oh come on, you know that's not my point. Does updating your phone take 10 hours?

 

[ven07]

Torcher makes a valid point.. Always plug in the phone before updating, just in case getting stuck on the spinning cogs happens from time to time and a soft reset is the right move in that case

 

[RumoredNow]

Did you unmount and remove your SD card first?