Liquid damaged WD Scorpio Black 250GB. Drive powers on but clicks. Heavy corrosion of the pins on the bottom of drive (see detailed pic attached). Any thoughts on the potential of cleaning the pins and doing a PCB swap?

the pins go directly to your preamplifier and the heads, there is a pretty good chance that the head stack will have to be replaced.

If you wish to try a PCB, then you will need to transfer the chip at U12 to your replacement board.

Otherwise try cleaning the preamp pads on the PCB with metal polish (eg Brasso) and a cotton bud. This works well with other electronic devices, but I have never tried it on a HDD PCB. Use isopropyl alcohol (audio/video tape head cleaner) and a toothbrush to clean up afterwards.

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