Hard disk drive surgery… Attempting to replace a head assembly – Part 1

Here’s the deal: bottom line… if you value your data – don’t improvise! If you’re not tech savvy and have no idea what you’re doing – again, don’t improvise! Hire someone who knows. Hire a specialist!


Replacing non-functional with functional parts on any hard drive is a delicate process and one that requires special tools to do the job. On top, you are expected to work in a clean air environment if maximizing the chances of a ‘full’ data recovery is your goal.

Take a look at this website to get an idea of what you’re possibly dealing with. Mind you, these are the mechanical parts only. For a full blown data recovery lab, you’re still expected to have a soldering station (the hot air one, as well as the contact type), a microscope, specialist software/hardware tools (e.g. from DeepSpar, ACELab (PC-3000), Dolphin Data Lab), and then some! But most of all, you need steady hands and a lot of patience!

Now, I’m certainly not a data recovery specialist, but my educational background (electrical engineering) and my inquisitive nature (and to be perfectly honest, a real life necessity too :)), drew me into this learning process: what does it take to successfully replace a HDD head assembly without any of the above?

10-Head assembly disassembled

Well, for one – I don’t own a laminar flow station. You could improvise something useful here (How to Make a Clean Air Enclosure (for HDD repair etc)), but as I really didn’t care if I completely damage anything in the process, I improvised.

I dusted off my desk and my work environment while leaving my air conditioner ON during the entire time to purify the air, turned it OFF and let everything ‘settle down’ before I opened up my patient hard drive.

I used these the entire time (so that I would simulate working under the same conditions as if I would attempt a real head replacement scenario):

00-Basic Tools

The first thing I did after opening the protective lid of the hard drive (a 3.5″ one btw!), was removing the top magnet from the head assembly actuator (I used curved needle nose pliers but again – there’s a specific tool for this as well):

01-Top magnet is out

I then inserted my ‘head tomb’ as opposed to a real tool for the job i.e. a head comb:

02-Head tomb is in place

A ‘tomb’ because you could basically bury the head here! This was my second improvisation and the light motive was borrowed from here: Hard Drive Head Replacement Tools for 50 Cents!

I don’t want to be judging, but: NECESSITY might be the mother of all (good) inventions, but IMPROVISATION happens to be the father of all screw ups! So be careful what you choose to improvise! This type of improvisation might work (for some!) but I definitely don’t think it’s worth the risk. There are alternatives – proper ones! – which are reasonably priced! Just search for hdd head combs and you’re bound to hit something on eBay, Amazon and/or AliExpress!

Surfing the Internet on the topic, I found (most!) people suggesting that the purpose of the head comb was to prevent the two magnets from touching thus permanently destroying the head? I ended up bending the head outwards (thus definitely damaging it!) but I cannot say I got the impression to confirm the previous statement. Maybe on a more delicate head assembly with gaps smaller than in my case!? I cannot say for sure, but my experience teaches me that the other purpose of the head comb might be to safely move the head pass the head ramp! I have to verify this again on another sacrificial hard drive!

Then, after removing the two screws – one on each side – I removed the ribbon cable:

03-Ribbon cable and connector is out

If in the previous step I was hopeful, this is when I  knew I definitely screwed up! I realized I should have removed the controller board first. That way, the strain exerted on the ribbon cable while removing it, would be less. Much less! Otherwise, you end up with a damaged ribbon cable (the first two pins are ripped off!):

04-Ribbon cable connector is damaged

Then again, this is an older drive, from a ‘not that reputable’ manufacturer and the way the ribbon cables are attached to the controlled boards on most other drives I’ve seen is much better – and safer! Still, make sure to remove the controller board first!

Top and bottom brakes are off:

05-06-Top and Bottom brakes are off

Controller board is removed:

07-08-Bottom ribbon cable and controller board are off

Do not remove these two screws (circled in red!):

09-Don't touch these screws

Otherwise, you end up removing the bottom magnet of the head assembly actuator and you don’t really need that! Trust me 🙂 I actually ended up removing all three (!) and the one circled in yellow is the one in this case – that frees the head assembly! Result: both the head assembly and the magnet fell off. Not good!

The final result:

10-Head assembly disassembled

And once more – everything back in its place:

15-Head back in place

Unfortunately, the hard drive no longer works! 🙂

But, I will not be my true self if I stop here, so I decided to give it a go once more. This time, I’m not going to use a head comb or an improvisation of any kind and see if I have more success – or buy head combs. But I’m pretty sure what the outcome would be 😉

And while preparing to wrap up… I came across this rather old(ish) article writen 5+ years ago, where the guy who wrote it, went literally through the same experience as I did. You should check it out. It’s worth the read: Hardware Tricks: How to Not Fix a Crashed Hard Drive.