WD Green Data Recovery Part 2: Head Swap, ROM Transfer, and Extraction

Two Failures, Not One

The Part 1 diagnosis identified a shorted preamp on the PCB. But swapping in a donor PCB only dropped the current draw from 2.5 amps to 2 amps; normal operating current is around 0.45 amps. The head stack assembly itself was also compromised, pulling 1.8 amps on its own. Both the PCB and the head stack needed replacement.

After both components were replaced and the patient's ROM chip was transferred to the donor PCB, the drive pulled 0.21 amps and initialized on PC-3000. Many recovery technicians doubted the Part 1 power-monitoring diagnosis. This video is the proof: the drive recovered successfully.

ROM Transfer and the First Failed Donor

Every drive's ROM chip stores factory calibration data (head position calibration, preamp tuning parameters, motor curves) unique to that specific unit. A donor PCB with the same model number will not work without the patient's ROM data. The technician desoldered the ROM from the damaged patient PCB and moved it to the donor board.

The first donor board matched the model number but did not work. Western Digital produces multiple hardware revisions for the same model, and the micro-code variants and ROM adapter codes differed. The second donor matched the model number, revision codes, PCB variant, and manufacture date (within three months). That one worked.

Successful Extraction via PC-3000

With both replacements complete and the ROM transferred, the drive connected to PC-3000, accepted the loader microcode, and began transferring data at normal speed. Normal transfer speed on a drive that was pulling five times its rated current 90 minutes earlier. The platter surface was undamaged throughout; the failures were electrical, not mechanical.