Hard drives and interface cards
All HDDs are fully tested. They are completely overwritten six times with the bit patterns represented by 00h, FFh, AAh, 55h, E7h and 18h.
The program performs 100,000 random reads for each pattern once the disk is 100% full.
The Windows program that performs the testing/erasing is available for free here.
Hard drive tips:
Always handle with care. Hold drives by the sides to avoid touching the circuit board. Mount them correctly - either vertically long side down or with the circuit board facing down. Very old drives from the 1980s are fragile when new let alone 30+ years later and require particularly gentle treatment.
When you receive a hard drive, especially an older one and especially during cold weather, allow the drive to acclimatise to the new temperature. Leave it in its bag for a few hours, maybe a day if the temperature change is significant.