Applies to all Maxtor DiamontMax & MaXline SATA drives! (Mine is 300 GB, 7200 rpm, 16 MB Cache SATA on Gigabyte 7N400 Pro 2 rev. 2)
Many people including me, can not recognize this drives or their motherboards are recognizing them hard, and mainly have problems with detecting them when cold boot.
All this drives have feature calld "Staggered Spin-up Detection". This feature is for servers &/or more than 2 drives to power up one by one, this makes the power supply's work esier when turning on such a system. This also makes it possible to run machines with multiple HDD's with lower power supplyes. They are cheaper also. Anyway this feature must bi off (Disabled) on PC's, or when there are one or two HDD's on the system.
By the SATA specifications the SATA HDD power cable is with 4 pins on the PSU side & 15 pins on the HDD side. By this specifications, Pin 11 is reserved (not used), and should be grounded or pulled low.
These series of Maxtor SATA HDD's are using this pin 11 for turning that feature on & off. When it is on, the HDD is waiting for more initializations more time that any standard Sata controller, Bios & motherboard will wait. So when it is off, the HDD acts like normal PC SATA drive.
Because this pin 11 is reserved for future use by SATA specifications, many SATA power cable manifacturers leave this pin going nowhere instead of grounding it (because it is not supposed to be used), but in our case it automatically enables the feature. So this drives auto sense if pin 11 is connected to power, not connected or grounded.
IMPORTANT: If Pin 11 is not connected or connected to power supply, that means that "Staggered Spin-up Detection" is enabled, & your HDD will NOT be recognized or not recognized all the time by the bios!
SOLUTION: Pull ot the power cable from the PSU & the HDD, and count 11th Pin, start counting from the side with the adge. Ground this pin to your case for example (to some screw)
More Info: http://www.maxtor.com/_files/maxtor/en_us/documentation/white_papers_technical/staggerd-spin-detection-pin11.pdf
Hope it helps everyone, sorry for the long POST & for my english, remember... I'am Bulgarian