Answer for:

external hard disk not getting detected

Message 4 of 3

View entire thread
0 Votes

1. Definition of unimportant data is data you don't bother to back up.
2. Hard to give any answer with so little information provided. Its like you don't care if you get an answer or not.
3. You never tried to put it in the original case and connect it to your brothers computer. (I distinguish betwee the "case" and the interface circuitry between the drive -SATA,PATA, SASI, what - and USB.)
4. USB devices are recognized by a Vendor ID that they return upon connection. Not all operating systems recognize all the VIDs. Some external drives render two VIDs one that requires hardware driver to be installed and another Lowest Common Denominator driver providing "USB Mass Storage" support. Newer drives require 4096 byte sector support, but some computers (adapters) only provide 512 byte sector support. Original Format may be an issue. Some external USB drives are "non-removable" so format is corrupted (format recovery software may, ~10% chance, work; but you never provided the error message) unless they are unplugged while power off (e.g. WD and Seagate drives with autorun software install to install driver that recognizes alternate VID or "one touch backup".) All this handling of the bare drive could have caused static damage to the drive electronics (plastic wrap can generate static electricity). (The $$$ solution is find someone with a cleanroom, get an EXACTLY IDENTICAL DRIVE, swap platter (/electronics) of bad drive with good drive.) Many Seagate and WD external hard drives have external power supplies, because many drives use +12V and +5V in excess of the .5A +5V maximum in the USB 2.0 Standard. (Your computer may have USB ports with higher current capacity which many USB peripheral suppliers depend on. Or it may have .1A USB 1.1 ports.) ( A +5V only 2.5" or 1.8" drive typically draws .65 to .35 Amp, plus USB controller current.) As mentioned your drive may have had a Y cable to "vampire tap" current from another port (data request required for full USB standard support). Some external drives have power supplies that can accomodate higher power draw drives by controlling drive duty cycle.