Swapped PCB & U12 Chip WD1002FAEX still not work.

[CrazyTurk]

Hello

In the begin I wanted to connect my HDD in a other computer. But I connected it with a wrong wire i think, becouse i used a Coolermaster modular cable in my XFX PSU, and then when i connected it my computer didnt want to power up. When i disconnected the power cable from my HDD then my computer powered up agian. So i think it was short-circuiting.

Now ive buyed a new PCB from this forum. Someone switched the U12 chip for me. And then i placed the PCB on my HDD agian. Then i connected it in my computer like all my other HDD's with the original cables. But then it did the same now agian. My computer didnt want to power up agian. So i disconnected the power wire from my HDD and then my computer powered up and my other 2 HDD's was working good.

Did i do something wrong ? or is my u12 chip broken ?

Please help.

Thanks

[CrazyTurk]

Oh yea and when i had the HDD plugged in when swapped the U12 chip and PCB. First the PSU gave a short kick to the fans and then nothing happend it didnt power up.

[Vulcan]

Based on your description, and assuming that your PSU itself is not faulty, those symptoms suggest to me that either:

(a) you have not properly fixed the incorrect power cabling to your HDD, so that you are damaging each "new" drive PCB which you use;

or

(b) your "new" drive PCB is also faulty.

If I was in your situation, those would be the two areas which I would investigate.

[CrazyTurk]

The power cables i use is the default XFX cables. They belong to my xfx psu. Ive tried it on my other HDD's and they still work.

But i measured R64 and R67 on both PCB's :

Old PCB : R64 is 00.5 and R67 is something like 58,8
New PCB with old U12 : R64 is 00.5 and R67 is 00.5

[Vulcan]

The power cables i use is the default XFX cables. They belong to my xfx psu. Ive tried it on my other HDD's and they still work.

At the beginning you said:

But I connected it with a wrong wire i think, becouse i used a Coolermaster modular cable in my XFX PSU

I have not seen you clearly explain what you have fixed, after your original comment. Anyway, it is your system, so you need to diagnose and fix whatever the original (cabling?) problem was, if you do not explain your analysis and any changes clearly.

I don't know what you expect, by giving the (limited) new info below. I'm not going to "talk you through" the diagnosis (not enough time for that, that's why I gave some brief suggestions earlier, of areas for you to investigate) but I'll give brief comments on this new data you have given:

But i measured R64 and R67 on both PCB's :

Old PCB : R64 is 00.5 and R67 is something like 58,8
New PCB with old U12 : R64 is 00.5 and R67 is 00.5

That shows that on the "old" PCB, R67 had been affected (probably as a consequence of TVS shorting due to power input overvoltage), and has increased its resistance.

The (correct) values of those 2 components which you measure on the "new" PCB, does not tell us that the "new" PCB is completely OK, nor does it explain why that "new" PCB also causes your PSU to shutdown. If I had that "new" PCB on my work bench, I would investigate the TVS; check the PCB off the drive; measure the expected voltages on each of the generated power rails; etc. etc. - just typical electronics diagnosis.

However it is also possible that you have been sent a faulty PCB - some members have reported that they do not always receive a working PCB from a supplier. So I suggest you remain open to that possibility during your troubleshooting, if you are sure that you have fixed whatever the original problem was, with your PC / PSU / cabling / etc.

[pcimage]

The PCB was got from me.

I tested it 100% before shipping and it worked fine.

I wrote a ROM from a known good drive to it and put it onto the drive, said drive functioned perfectly with this PCB.

[Vulcan]

@pcimage:

Great, so that possibility is eliminated.

So either drive preamp is faulty, or the PC / PSU / cabling still not fixed, despite what the OP says. Assuming he hasn't damaged the PCB, I don't see any other explanation for the reported behaviour with that known-good new PCB

[CrazyTurk]

Oh wait ive typed it wrong.

I used XFX cable in a coolermaster PSU and i think they are wired different. And becouse of that i think it short circuited

[Vulcan]

Oh wait ive typed it wrong.

You will not get useful / correct advice, if you supply wrong / unclear information

I used XFX cable in a coolermaster PSU and i think they are wired different. And becouse of that i think it short circuited

I don't know (or care) what an XFX cable is. This is not a PC support forum - it is your responsibility to provide the disk drive with the correct voltages, on the correct pins.

If (as you seem to be saying) you have not fixed the original power cable problem, before using the new drive PCB, then of course the same result is expected as when you were using the old drive PCB! You might also have now damaged the new drive PCB.

See point (a) in my first reply in this thread, for what seems to be the situation (based on your comments).

[CrazyTurk]

I have fixed the wire problem before trying the new PCB. And the same thing just happend agian.

[pcimage]

DIY time over