The highest level of skill is required to replace damaged heads – without damaging something else in the process. The heads are connected via suspensions and arms to an E-block that has bearings in its hub. This assembly, with a portion of the voice-coil motor actuator, is called the head stack. When heads are replaced, it is easiest to replace the entire head stack. This is also referred to as a head transplant.
Great care is necessary with the replacement head stack to ensure that the air bearing surfaces of the heads (actually the “sliders”) do not touch each other. This is because they can easily damage each other or even stick together. When removing the damaged heads, it is important not to drag them across the disk and cause more damage. Ideally custom tooling, such as a special comb, will be used to lift the sliders off the disk surface before removing them.
Equal or greater care is necessary when loading the good heads back onto the damaged drive’s media.
