I always keep the PCB from crashed hard drives; I've got a few boxes full of them, from brands such as Conner, DIGITAL, IBM, Micropolis, Quantum, Seagate, and WD. Useful for converting drives from IDE to SCSI (when possible, such as between similar versions of old Quantum Fireballs) and for resurrecting drives that have blown their original board. I've seen several drives with charred microchips that work fine when the boards are replaced with one from the same model.
It's possible that the controller could be failing, but since it's a Maxtrash, it's more than likely a problem within the HDA. Often, as a drive ages, the platters or heads degrade to a point where they can no longer properly register the magnetic signals. The controller attempts to figure out what the signals it's receiving are supposed to be (1 or 0), and if it can't readily determine that, it'll reread the same sector or cylinder over and over until it gets some consistent results. Then it'll accept the result and do whatever it's supposed to do with it, and move on. If the drive is failing, the read/reread cycle will continue as it encounters even more sectors that it can't get a positive reading for. PRML drives can be pretty bad about that, especially the cheap ones.