i have about 5 h.d.d same model 3 of them failes with same symptoms, there not being recognized from time to time, during boot time(checked on multiple machines).
is it even possible to update firmware? (i guess so, as i have seen here firmwares updates), the problem is that i have no clue how to handle those file (.rpm..)
can anybody please help, such noob like me?

wd1600aajs - 00b4a0
s/n (for one of them) wcat18489101