Hi Guys,

I received today this moel for the first time - Samsung HD501LJ 500GB drive and the drive doesn't start at all, which indicates a PCB Failure.
The TV'S had some green corrosion on them so i removed them and cleaned the PCB. I don't see any other obvious damage and i don't have a donor drive to compare components.

Drive still not spinning after removal of the TV'S,
I attached the pictures of the PCB and model.
If someone familiar with the drive it would be great to point me into the possible failing components to check.

Thanks

Does the chips get hot after you power it on?

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It's pointless to try to repair these PCBs unless you have everything like combo ICs and spare MCUs and all discrete components and want to spend some time. I do it only in two case : emergency and mass repair.

In my opinion it is a total waste of time, if the purpose is to get data (and ca$h) as soon as possible. Just do a quick test if there is activity and power at MCU / CIC / port, if everything is flatlined and you don't see any evident problem in 5 minutes, get another PCB /donor and make it work with your HDA (if it is only the PCB).

I've repaired many of these boards. Did you actually measure the TVS diodes before you removed them? If one of them were shorted, then the associated zero-ohm resistor or polyswitch would be open circuit, in which case the simple solution is to bridge it with a wire link in the vacant spot directly alongside it. It goes without saying that you should retest the board for shorts before powering it up again.

If you don't have a multimeter, then you should find one at DSE or Jaycar for AU$10. My TVS diode FAQ explains in detail how to make the appropriate measurements.

In short, a fix should cost you nothing.

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A backup a day keeps DR away.

Did you test the TVS before removing? Very simple 1 step process to test them, best to do that before just pulling them off in future.

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Hi fzabkar, thanks for your reply.

I didn't test them out, but they are on my table, i can test them tomorrow.
They has green corrosion on their connectors so i assume one of them was surely bad, the 12V one looked bad.
I have a decent multimeter but i don't know me electronics that good.
I read the TV'S faq which is pretty good thanks for sharing that.

I am still not clear about few things you write:
1. Where is the Ohm resistor or polyswitch on the picture above? how do i identify them?
2. Which lines of 12V & 5V? as defined in SATA Power pins (13-15, 7-9) should i start measure the circuit from there?
3. Didn't quite understand how to test for short the whole circuit, black probe to ground? red probe to where?

Thanks for the assistanc

Yes i hurried to pull them out before testing them, that was a bit hasty.
I usually test them, but these ones were looking bad.

Non of the components on the board are overheating.

I had a look again on the picture and there is a large component opposite pins 13-15, is this the Polyswitch?
I tested it earlier for continuity and it was OK, should i wire link that with the Diode Pad?
And how do i check for other shorts than as you suggested?

Here are photo clips that should help you identify the components:
http://www.users.on.net/~fzabkar/HDD/HD ... switch.jpg
http://www.users.on.net/~fzabkar/HDD/HD103SJ_TVS_2.jpg

As for your drive, the polyswitch is designed to reset itself after an overload. However, the resistor will go open circuit and remain that way. If you find that it is open, then flow a blob of solder over it, or place a wire link in the blue box alongside it. Then test each of the supplies for short circuits.

_________________
A backup a day keeps DR away.

thanks for your answer.
I checked continuity on both the Zero-Ohm and the Polyswitch and both were ok, not open.

Maybe it's faulty motor chip...

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.... then good luck.

Bummer, no ROM on this one, need to transfer the controller

... assuming it is working. And I have a certain feeling.....

Why all this hassle when you can find a donor board and make it work (assuming headstack is OK) ?

Measure the voltages at each of the three coils with respect to ground. Also measure the voltages at the 3 pins of the transistor. Be careful not to short adjacent pins.

If there is no output, then the motor controller must be suspect.

Take your measurements with the PCB removed from the drive.

_________________
A backup a day keeps DR away.

Thanks for your assistance.
So in order to check the Voltage in respect to the ground:
Do i need the black probe on the SATA Interface Ground Pin and the red probe on each side of the tested coil at a time?

Yes.

_________________
A backup a day keeps DR away.

I tested the diodes, the 12V was defected.

Regarding the COIL measurement with ground, i couldn't get a stable reading out of it.
The 3 leg transistor displays values on measurements, but for all of them the Multimeter zeroes pretty quick.

Just to be sure, have you selected a DC voltage range for your measurements?

If the 12V diode is shorted, then this would suggest that the motor controller may have been damaged by an overvoltage. The motor controller generates all the voltages for the other ICs. That's what your voltage measurements are looking for.

_________________
A backup a day keeps DR away.

This Multimeter has Autorange so as far as i know i don't need to set it up, but something doesn't feel right with the measurement.