Samsung F3 HD103SJ - success story and PCB fix help pls

[aszu]

Hello,

Recently, when doing some cable management in my PC, I stupidly managed to damage PCB on my Samsung F3 - one of these square resistors (4R7) got disconnected from the board (photo attached).
I realized that when disk suddenly stopped being detected by BIOS/Windows.

I found this disconnected resistor and tried to re-solder it, but it did not work for some reason (test with multimeter went just fine).

Disk is completely dead, it is not even spinning. Also, when connecting SATA power to the disk it looks like that PSU overcurrent protection kicks in (PSU makes weird noise) - something is shorted? :/ I checked TVS and it *seems* to be OK, although I am not sure if I am checking them correctly. Diode test shows some resistance in one way and in other way there is no current flowing.

The success is that I found almost identical disk on ebay (manufactured 2010/5, mine is 2010/4), swapped the PCB board and my broken disk was brought back to live straight away, with all the data left intact! No messing with firmware chip, etc - it just instantly worked. So I am sure that the disk itself is OK, only something wrong happened to PCB.

I would like to fix this PCB. Do you thing it is possible? Also, is it possible that PCB got damaged because for some time disk has been powered on without this resistor?

Could you please offer me some advice where to start and what to test/check?

Thanks!

Attachments

[fzabkar]

The "4R7" component is a coil. It appears to be associated with either the Vio or Vcore supply, probably the former. It should measure close to zero ohms on the 200 ohms range of your meter.

Did you disturb the coil while the drive was powered on? If so, then you probably damaged its associated MOSFET chopper and/or the Schottky flywheel diode inside the adjacent motor controller chip.

As for why your drive appears to be overloading your PSU, have you correctly identified the TVS diodes? These are the two larger components near the SATA power connector, at the bottom left of your photo.

The test points for each of the DC-DC converters are ...

(1) the plated through-holes below and to the left of the subject 4R7 coil,

(2) the plated through-holes to the left of the other 4R7 coil, and

(3) the third pin from the right, on the bottom row of the 20-pin preamp connector.

AIUI, voltages (1) and (2) would be Vio (+3.3V or +2.5V) and Vcore (approx 1.2V to 2V), while voltage (3) would be the negative supply for the preamp, probably -5V.

[aszu]

Many thanks from the answer! I know it has been a while though...
I finally got some time to check this drive out again.

As far as I remember, the disk was not powered on when the damage occurred. However, I powered the drive later on without this coil, I think I also tried shorting coil contacts with solder and applying power (don't remember exactly...)? Would that cause any damage?

It might be a silly question, but is this coil very badly required? If I just bridged the contact with solder, etc, should at least the motor start?

Bare PCB (detached from the drive) connected to the power supply does not cause shot, does this imply that TVS is OK?

I am thinking about ordering this thing and replacing the coil (I lost the original one...):

http://www.ebay.co.uk/itm/INDUCTOR-POWE ... 3cca2465cc

Would it be OK? However if there is some further damage to the PCB, I might just forget about this disk - is there an easy way to test this?

[BGman]

It takes a few minutes to get such a coil from a non-working PCB and solder it ....

[aszu]

Sadly, I do not have any spare PCB with such a coil.
What would happen if I just bypassed it completely?

[BlackST]

If it worked with a wire they would have put a trace on the PCB and save thousands of coils. Understood ?

[SAjunky]

Sadly, I do not have any spare PCB with such a coil.
What would happen if I just bypassed it completely?

I think you already did it, as you keep asking the same question. As fzabkar wrote the coil is a part of DC-DC converter. Mess up with regulators, you can blow regulator chip or even worse, damage preamps inside HDA.

[codeyla]

Hey guys,

I have exactly the same problem as aszu did (I managed to drop my drive which took off the 4R7 coil and broke it, although nothing else looks broken...), so my question is pretty predictable: does anyone know where I could buy an identical replacement coil (or cheap dead PCB with a coil on?)? And if not, would this or anything similar be sufficient to make the disk work again? http://uk.rs-online.com/web/p/wire-woun ... s/6142778/

Thanks very much!

[BlackST]

Hey guys,

I have exactly the same problem as aszu did (I managed to drop my drive which took off the 4R7 coil and broke it, although nothing else looks broken...), so my question is pretty predictable: does anyone know where I could buy an identical replacement coil (or cheap dead PCB with a coil on?)? And if not, would this or anything similar be sufficient to make the disk work again? http://uk.rs-online.com/web/p/wire-woun ... s/6142778/

Thanks very much!

I have a feeling your drive have something MORE SERIOUS issue than a broken coil.

GOOD LUCK.

P.S. I wouldn't power it on, but it's me.

[Vulcan]

@codeyla,

I managed to drop my drive which took off the 4R7 coil and broke it, although nothing else looks broken [my highlighting]

FYI since you've dropped the drive, there could be internal mechanical damage that you can't see - just because nothing else looks broken, doesn't mean it's OK. Powering-on a drive in that state can cause further problems and reduce the chances of successful recovery.

would this or anything similar be sufficient to make the disk work again?

If you accept all the risks of your planned DIY repair, and have good soldering equipment and skills, then that component from RS may indeed be electrically close enough to substitute the original one (you'll need to check the mechanical fit too, or else use some ingenuity when mounting it). However for the reason above (or others), your repair attempt may not be successful. Your risk, your choice.

Edit: While I've been typing this, I see that BlackST has also given you a similar warning