Hi,

All my google searches lead me to this site to help with my hard drive.
I have the following drive with a fried PCB due to a power supply fault :
Model: Samsung HD 103UJ
Size: 1TB
Date: 2009.02
PCB: Trinity 32MB REV 5
BF41-00206B R00

As suggested in other posts, I tested the PCB using a multimeter and found the 5V TVS Diode to be short circuited and the zero ohm resistor next to it is open circuit.
So I removed the 5V TVS diode and soldered a wire over the zero ohm resistor and now the drive appears to be fully functional.
So far so good and I am now backing up all the data on the drive.

My question is about the parts required for a more permanent fix and the reliability of the drive.
I can easily source a SMAJ5.0A to replace the diode, but I'm not sure what to do about the zero ohm resistor. I have looked into a possible fuse replacement, but I'm not sure of the operational current range. I read of using a 2A picofuse - is 2A the correct size for a permanent fix ?
Also, there is a further restriction due to the size of the resistor being only 3-3.5mm in length (a pico fuse is twice this).
So would this item be appropriate: http://www.farnell.com/datasheets/48294.pdf ?

At the moment the drive appears to be fully operational, so is this an indication that the drive could go on to live a healthy life with the replaced parts ?
Or are there hidden dangers to watch out for ?

Many thanks,
Michael

Thanks very much for your feedback.

I had always suggested a picofuse because I found them easier to obtain, and they are easier to handle. However, you appear to have found the ideal replacement. In fact I have seen smt fuses in some Samsung drives that were marked with an "N". Your datasheet confirms that these are in fact rated at 2A.

Anyway, congratulations on your repair.

As for future reliability, you can always expect some insidious failure. But then you can say the same about refurbished drives, or used PCBs.

Mikey, can you post a photo of what you did exactly? I have exactly the same situation but not sure exactly which area to solder.

This photo clip should help you identify the components that you need to test:
http://www.users.on.net/~fzabkar/HDD/HD103UJ_TVS.jpg

_________________
A backup a day keeps DR away.

I'm a super electronics newb fyi.

In diode mode, I get
700 on the first black diode.
A quick spike of 050 on the second black diode and then a drop to 001 or 000.
030 on the right "000" element.

I'm guessing the middle second black diode is dead?

Would you solder a wire connection to circumvent the black portion? Do I need to remove that black diode first?

Thanks a million.

Remove the 5V TVS diode, and flow a blob of solder over the zero-ohm resistor ("5V fuse").

If there are no other problems, then the drive should be OK. However, make certain that your power supply is good, as you will have removed the overvoltage protection from the +5V input.

For continued protection you could replace the diode with an SMAJ5.0A.

_________________
A backup a day keeps DR away.

Is the zero-ohm resistor the right smaller piece, correct?

Ahhh freakin awesome! Its back. Copying all my old files off now. You're a total hero.

@fzabkar. I could really use your expertise, or anyone else for that matter regarding exactly where to run this solder blob. email or pm me.

@rudeco, if it's a HDD, then upload a photo. If it's some other device, such as an LG Optimus Slider, VM701 cell phone, then a different forum would be more appropriate. For example, try the sci.electronics.repair newsgroup. A lot of experienced technicians hang out there. I have no experience with mobiles, BTW.

_________________
A backup a day keeps DR away.

I appreciate the advice, but a local electronics shop told me that hdd pcb are very similar in that they are low voltage boards. I cannot find any other forums relating to phones and repairs of this nature. Could I still post a pic of the board and get some direction as to which is which component. I would assume the risk in the event of mistake being that its not an hdd. Thanks and lemme know.

Any device powered by a battery will usually be a low voltage device.


http://groups.google.com/group/sci.elec ... topics?lnk


My access to this forum is already crippled. I don't want to risk being banned by engaging in an off-topic discussion. Sorry.

If I am unable to help you at sci.electronics.repair, then there are several other more experienced and knowledgable technicians and engineers amongst the regular contributors.

Be aware that Usenet is text-only, so you'll have to upload your photos to a file sharing service or the like.

_________________
A backup a day keeps DR away.

I went ahead and did that. Plus I uploaded a photo of my PCB to flickr.com and here is the link. http://www.flickr.com/#/photos/77872404@N08 , you can see the burned out diode laying alongside where it was removed on the upper right hand side of photo near the power port. My main question is if that tannish beige diode next to it is the ohm resistor / fuse that I would need to bridge.

@fzabkar, I posted on that group, just search my name, rudeco, or lg optimus. Thanks for the input guys, really appreciate the help.

sorry guys, correct link to that pcb photo is http://www.flickr.com/photos/rudeco

Hello folks !
First time that I post here, and it's just to say you did a wonderful job !
I had a Samsung HD103UJ and I was disposing it, but walking around in the web I'v got you hint, and now it's 100% working !

Just a question, really two:

- the Zener 5V usually is supplied at 4,7 V, is that a problem ?
- what is the purpose of the zero Ohm resistance ? Can I leave it jumpered with that blow of solderer ?

Thanx a lot and all the best !