Hi guys, I am new here. I hope this not wrong thread.
Ok, here's the things.

I've 2 different HDD. 1 WD Caviar SE (WD1600AAJS-22WAA0) 160GB & 1 Maxtor DiamondMax 22 (STM3320614AS) 320GB.

The WD1600AAJS-22WAA0 power on but cannot detected by BIOS and when I used it with USB Enclosure, windows cannot detect too. In my mind, its no good. What I am supposed to do, if I want recover the data?
And
With STM3320614AS, my BIOS (the SMART) give notice: BAD. Can I repairing it?

Any suggestion, I trully thanks.

_________________

The Maxtor drive probably has exceeded the threshold value for the number of reallocated sectors. Try a comprehensive SMART diagnostic. Look for reallocated, pending, or uncorrectable sectors.

HD Sentinel (DOS / Windows / Linux):
http://www.hdsentinel.com/

HDDScan for Windows:
http://hddscan.com/

See this article for SMART info:
http://en.wikipedia.org/wiki/S.M.A.R.T.

As for your WD1600AAJS, it is a member of the Tornado family. These often had problems with the MCU chip (88i6745) on the PCB, but I'm not a data recovery professional so I can't say whether this is the problem in your case. The rule of thumb for most drives is that, if the drive spins up but is not detected, then the problem is most likely internal.

_________________
A backup a day keeps DR away.

No SMART test will solve your problem (on the Maxtor) neither "cosmetic" solutions will. And no DIY.
Have the drive completely fixed by a pro (should be very cheap) if possible (if media or heads are degraded there is still a plan B with limited lifespan). The more you fiddle with it, the worse.

The WD instead may be "relatively simple" problem on professional point of view OR bad problem (need diagnose). But again no DIY.