Fixing iPods

Diagnostics

Key combinations

See the graphic at http://www.command-tab.com/2006/03/30/hidden-ipod-commands/ for key combinations.

iPod 5th gen

MENU+SELECT

restart

SELECT+REVERSE

diagnostic mode

Disk repairs

Skipping bad blocks

See http://www.openobject.org/isop/?p=47 for how to re-partition an iPod's hard drive so that bad blocks are part of the partition-map partition instead of the firmware or data partitions. I've successfully used the routine there, but with a firmware partition twice the size. Make sure you're using the right size for your device by listing the existing partition map and printing it or saving it in a text file. I also made free space partitions usable space instead of enlargening the partition map, which doesn't always work. Here's my modified map of a 30GB fifth generation iPod:

Partition map (with 512 byte blocks) on '/dev/disk1'
 #:                type name       length   base     ( size )
 1: Apple_partition_map Apple          63 @ 1       
 2:          Apple_Free Extra     2097088 @ 64       (1024.0M)
 3:          Apple_MDFW firmware   131072 @ 2097152  ( 64.0M)
 4:           Apple_HFS disk     56300000 @ 2228224  ( 26.8G)
 5:          Apple_Free Extra       76896 @ 58528224 ( 37.5M)
Device block size=512, Number of Blocks=58605120 (27.9G)

See http://www.macgeekery.com/node/6 for nice examples of partitioning that helped people with both new and old disks.

Take-apart guides

Good guides are at iFixit.com, for example their page on the iPod 5th generation (Video): http://www.ifixit.com/Device/iPod_5th_Generation_%28Video%29