I have a Series 3 (OLED) that needs a new hard drive. The current ones failed the WD extended test so I'm looking to simply get another 250GB one since this is not a heavily used unit. Its used in a basement rec room and more or less a cable box for down there (with occasional MRV to Premieres upstairs). While I am not sure I would do this & its really out of curiosity, I searched ebay for some 250GB Western Digital drives since this size doesn't seem to be available in new units. Came across one that said the drives have "been wiped and passed a surface scan" Is a "surface scan" thorough enough? Or can there still possibly be problems similar to what was detected on my current TiVo hard drive (via an extended test only).