Power LED (green)
|Blink||At bootup, prior to ppc_uartd starting, Just prior to ppc_uartd starting to write to flash memory|
|Blink Slowly||Setting timer|
If ppc_uartd is not started for some reason, it remains blinking, and then after few minutes, DIAG LED blinks 6 times(hard disk error), 6 times, 6 times, ... finally the box shutsdown.
DISK FULL LED (red)
|blink||Writing to flash memory|
DIAG LED (red)
|3 times blink||Partition warning: /dev/hda3 is not mounted on /mnt. You can ignore it.|
|4 times blink||Problem with the cooling fan - probably rotor jammed.|
|5 times blink||Problem with the flash memory*|
|6 times blink||Hard drive not found. Or ppc_uartd is not running.|
|7 times blink||Problem with the RAM/LAN/HDD controller.|
|blink many times||Writing to flash memory.|
* Sometimes, you can recover from a flash memory error by pulling out power cord and try again after one night.
Table copied from http://www.yamasita.jp/linkstation.en/led.html with minor rewording. nobuakiy helped with the translation.
Notes Users have reported problems when the drive already has a Linux partition on it - the diag light blinks 6 times. The solution appears to be to simply to reformat the drive.