Hello.... Im new to this, so any help would be greatly appreciated.

Ok, so a few days ago my pc didnt boot up. Long story, short, one of my 2 Hitachi hdt721050sla360 500Gb hard drives wasnt spinning. HD0... which I assume is where windows is kept? After messing around with it, I tried swapping the pcb from HD1 and sure enough it started to spin. The computer detects that "something" is connected but cant sense that its a 500gb hard drive. so it still doesnt work.
My question is, is there any way to get it to work if i was to order a new pcb?
And if not, and i was to purchase a new hard drive, and reinstall windows to it, would i be able to save the stuff on the still working hard drive?
Thanx in advance.

Ok here is your probhlem. You HDD PCB is burned for one. Another PCB showed you this one but problem number two is that adaptive in NVRAM are not the same and so that is why it is still acting up.

You need to understand how to get adaptives from NVRAM to move them over to another PCB and the PCB should be compatable with the one you have.

You can try searching around here tor TVS on this drive but I do not have one in front of me and can not tell you right now if it has TVS or not on this board. Sorry but you can still search here and see if your drive has a TVS and check the reading from it and see which one is bad. That is if there is actually a TVS to do this one with.

If you can get it to work again clone it to a new HDD and this will move all your data from one drive to another. You can use DDRescue to so this one

Now for the working HDD. Was this a second drive on your computer or was this a RAID system set up on your computer? It is hard to say how you have this set up you did not answer or say how it was set up in the first place. So if this is a second HDD and used for storage then yes you can still use it and just get a new HDD and install windows on it. If it is part of a RAID this might be a mirror drive not sure but it could be. So there is a lot you have not said so it is hard to answer questions for you. More details would be better if you want some answers.

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Iorana Haraharaini

If you upload a photo of the component side of your PCB, one of us will show you the location of your NVRAM.

BTW, if your PC powers up and POSTs, whether or not it boots afterwards, then your TVS diodes would be OK.

I'm assuming your diodes look like these:
http://www.users.on.net/~fzabkar/HDD/HD ... 60_TVS.jpg

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A backup a day keeps DR away.

Yah it booted becasue he took the pcb from his other drive and put it on the dead one. Then the drive spun up but not before. First off it would not boot up until he moved the pcb to the dead drive. So guess his TVS diodes are dead.

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Iorana Haraharaini

Do you understand the difference between "booting up" and "powering up"?

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A backup a day keeps DR away.

Aita vau paraou Tahiti

Maruru

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Iorana Haraharaini

Thanx for the replies... I think I know what a raid system is, but to make things clear... when I went to "My Computer" there was only a C: drive showing for HDD.
The Bad HDD sits in a slot that was labled HDO in the tower, and the good one was in the HD1 slot.
And what exactly is a TVS?

Why do you take professionals posts and twist them around for your own weird satisfaction? I see this time and time again when a professional posts something and you run to it and add your 2 cents when it's not needed. Almost like forum spam. Is there some reason why you feel the need to do this?

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Buy your friends Toshiba\Hitachi and your enemies Seagate.

Ann is in the habit of ignoring what other people write, not just in this thread, but in several others.

In my first post I explained why I thought that the OP's problem was most likely not related to TVS diodes, and I did so politely, without addressing her error directly. Yet she subsequently refused to consider my point. That demonstrates a lack of respect on her part.

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A backup a day keeps DR away.

The 8-pin NVRAM chip is located at U5, to the right of the Samsung SDRAM.

The TVS diodes are as in my photo clip.

See http://www.users.on.net/~fzabkar/HDD/TVS_diode_FAQ.html

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A backup a day keeps DR away.

Let me try this one @ Franc

1 (my hard drive is not spinning) + 1 (I took the PCB from other drive and put it on this one) = 2 (now my HDD is spinning but still is not recognized)

Now you say 1 + 1 = 3 which means THIS IS NOT A TVS PROBLEM

I guess you win Franc. This is not a TVS problem.

@mauricon69

I will send you a PM so my words are no longer twisted and I am no longer stupid if a PC boots or powers up. I fully understand your PC is powering on but can not boot to the HD0 becasue you have a drive that is not spinning at all (dead) and this one more than likely has your OS on it. But if you move the PCB from the other drive to this one your HDD is now spinning but still can not boot correctly to the OS. When your system powers on the second HDD does not contain your so you are correct on this one. But your second HDD is not bad.

You can go ahead and get a new HDD and install your OS on it. But if you can get an matching donor PCB and move over the U5 NVRAM chip to the new PCB you can clone this drive using ddresecue and get off the data. I would get a new HDD and also a matching PCB for HD0 as you are calling it now. Move over the U5 NVRAM that holds the drives adaptive to the new board. Then with ddrescue clone to the new HDD and put them back into place.

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Iorana Haraharaini

Thank you so much. I love this one. Everyone can not accept their own faults when pointed out they have to run behind and blame someone else. It is never their fault it is always another person. OK so this time it is me and who will it be next. You want to know something I personally do not care. You can bad mouth me all you wish and say what you like about me. But facts do not change no matter how you add them up. You were asked why you do as you do and the only response you can give is to blame me for a fault that you have.

I saw another post where it is Quasimodo and another one it is BlackST and another one it is someone else. But it is never you. The cards do not add up why all professionals are personally attacked by you and we are always in the wrong. I have no clue what this one means.

Franc I know you will sit and stew over this one and I am 100% sure you will respond. Too bad I did not buy a lottery ticket I would be a millionaire right now knowing the out come of this one.

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Iorana Haraharaini

@Ann,

There are two typical implementations for TVS diodes in HDDs. In one case, the diodes are connected directly across the +5V and +12V supplies. In the second case there may be a fuse or resistor or polyswitch in series with the supply.

Knowing this, I searched the Internet for a photo of the OP's board. I then searched my collection of photo clips for a photo that matched the OP's PCB layout, and I linked to it for all to see. Had you examined the photo, which I had annotated for everyone's benefit, you would have seen that both diodes were connected directly across the supply rails. Therefore a shorted diode would have resulted in a direct short circuit at the PSU connector. This in turn would have caused the PSU to shut down, which would have meant that neither of the OP's two drives would have been spinning.

In fact the OP stated that only one drive, which he presumed was his OS drive, was not spinning. Clearly, a failure of his OS drive would explain why his system was not booting (as distinct from not powering up).

Therefore, I concluded that neither diode was shorted. That said, it is possible that a TVS diode may have failed in the open circuited state, but that would be an extremely unlikely failure mode.

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A backup a day keeps DR away.