After booting with a new power supply and new usb power cable, *and* leaving an optical mouse disconnected, I get sustained power levels of 4.88-4.99V. But I still get freezes randomly, and reboots that result in kernel panics.
I waited a good 15m for it to unfreeze before power-cycling. Upon reboot, I get one of two things: a severely corrupted fs, with fsck spewing out lots of double or orphaned inodes, eventually dropping me to a prompt to do an unautomated fsck (which is usually fruitless), or more, commonly, it logs finding the mmc0 SDHC card, some lines about usb devices and hub, then
EXT4-fs error (device mmcblk0p2): ext4_map_blocks:577: inode #8: block 10658: commm swapper: 1block 334 mapped to illegal pblock (length 1)
jbd2_journal_bmap: journal blcok not found at offset 334 on mmcblk0p2-8
JBD2: bad block at offset 334
JBD2: IO errot -5 recovering block 334 in log
repeated for blocks 335, 336, 337, and 338
then some more lines about usb and ehternet, keyboard, etc., then
JBD2: recovery failed
EXT4-fs (mmcblk0p2): error loading journal
List of all partitions:
[some lines here about partitions]
No filesystem could mount root, tried: ext4
Kernel panic - not syncing: VFS: Unable to mount root fs on unknown-block(179-2)
First time I boot these images, they work fine. It's only after either freezing or powering down properly that they go corrupt.
One card is a SanDisk 4GB class 4 microSDHC in a SD adapter.
The other is a PNY 8GB class 10 "Professional" rated at 20 MB/s.
Both exhibit the same behavior.
Should I try buying a third?