Ds-80249 -p Rev 1.2 Schematic Upd -

If your DVR boots but doesn't "see" the drive, check the MOSFETs (often 8-pin SOIC chips) that gate the power to the SATA headers. On Rev 1.2, these are often switched by the CPU to allow for staggered spin-up of multiple drives. 3. Key Differences in Revision 1.2