IBM malfunctions

Manufacturer: IBM, drive families: DJNA, DPTA, DTLA, AVER, AVVA
Malfunction signs: A drive spins up the spindle motor, recalibrates itself, reports on readiness, BIOS identifies it correctly but at a reading attempt the drive produces “scratching” sounds and reveals numerous BAD sectors on its surfaces.

That malfunction is connected with a mismatch between the cyclical redundancy check code in the data fields and the information recorded in the sector service field. Such a situation appears when recording to a sector is unfinished. That may result from lack of contact at the connector between the PCB and HDA. That connector consists of needle-like pins touching tinned pads on the PCB (please see figure 11). With time soft solder becomes perforated and contact quality deteriorates.

Figure 11. Pin contacts of magnetic heads’ assembly connector in IBM drives (view from behind the PCB)

In order to repair that malfunction you should remove the control board, clean the old solder off the contact pads and cover them again using silver-based solder, then carefully wash the soldered location. Install the board back to HDA. Then you will have to clear the whole disk surface overwriting it with any code using freely available software (please see part 4); that will accomplish recording of correct CRC codes.