Basic Disk Drive Maintenance

Platters in disk drives always spin the same way--counterclockwise. A typical 3.5" drive found in today's computers rotates at 7,200 RPM. That's almost 4 billion revolutions per year! All this rotation in the same direction leads to uneven wear and shortened tread life. In addition, your hard drive may perform poorly in rain or snow. You can significantly extend the life of your disk drive as well as improve handling by rotating your platters every 3,500,000 to 4,500,000 revolutions.

Step 1. Opening Up The Drive Case

Before you start, take a few minutes to clean up your workspace. If you're going to be working in the garage, make sure to carefully cover any bags of cement, fertilizer, or other particulate matter. Pets should not be allowed in the work area at any time. As for clothing, standard cleanroom garments are best, but a plain T-shirt is ok as long as has been freshly laundered.

It's best to do all platter rotation in a Class 10 cleanroom environment. If you don't have access to one, wash out your Shop Vac and put a new filter. Direct the output of the Shop Vac over the work surface. And remember, all employees must wash hands before returning to work.

With the work area cleared, you can go ahead and open up the drive. Ignore any "Warranty Void If Removed" stickers; just peel those suckers off. (Those disk drive companies just don't want you to do any preventative maintenance on your drive so it will wear out faster and you'll have to buy a new one.) Remove all cover screws and set aside, as Ronco here demonstrates.

Step 2. Removing the HSA Stops

Our next goal is removal of the head stack assembly. You may have to first remove a physical stop which restricts the HSA's range of travel to locations which actually touch the platters. Frequently, removal of the stop requires a special tool.

Since you don't own the special tool, you can use a pair of Vise-Grips, as Frostbyte illustrates at left.

Step 3. Removing the HSA

With the HSA stop removed, it is simple to remove the HSA from the platter region. It is not necessary to remove the HSA completely from the drive for this operation. After extracting the stop, rotate the HSA counterclockwise until the HSA is out the outer diameter of the platters.

Before you slip the HSA off the platters, you'll need to take a few precautions to make sure you can get it back on. Each head is held against the platter surface by a flexure; once removed from the platters, the flexures will unload, pressing adjacent heads into one another and making it nearly impossible to re-insert the HSA. To prevent the flexures from moving, insert the manufacturer's recommended flexure comb (special tool) into the HSA before completely disengaging the HSA from the platters.

Step 4. Lock and Unbolt Platters

Don't own the special tool? In a pinch, you can use extra-small binder clips or a plastic comb to hold the flexures in position. If you use the comb, make sure you clean all of the dandruff out of it first.

With the flexures stabilized, you can swing the HSA out of the way as shown at left.

With the HSA out of the way, the platters can be removed. First prevent the platters from rotating by ramming a chock block somewhere inside the drive enclosure. Next, unscrew the fasteners from the spindle chuck, at arrow at right.

Step 5. Remove, Rotate and Re-install Platters

The platters and spacers can now be safely removed from the drive. Remove all the platters, carefully storing them as shown on right. Be sure to store all platters in the same direction, i.e. all top surfaces away from you. Do not touch the surfaces of the platters or you may wipe off some of the magnetic data.

After all platters have been removed, platter rotation is accomplished by simply re-installing each platter in order, but upside-down from its prior configuration.

Step 6. Re-insert HSA

With the platters re-installed, rotate the HSA back into normal postion and remove the flexure comb. If you didn't use a flexure comb, try holding all 18 to 22 flexures in exactly the right position while simultaneously rotating the HSA clockwise. It won't work, but at least you can say you tried.

Step 7. Clean-Up

Reinstall the HSA stop and automatic parking mechanisms. Give the whole drive a nice blast of ozone-depleting chemicals. Reattach the spindle chuck and tighten each screw to about 1 N m of torque.

Step 8. Completion!

Now screw the drive case back together, and you're done!

Wasn't that quick and easy? You just saved yourself the time and expense of having someone else rotate your platters for you! With a little care, you can perform this job at home with exactly the same results that a professional would achieve.

You'll notice the difference in your drive's performance immediately.