Samsung HD154UI - 1.5TB DEAD...

[fzabkar]

If you have indeed correctly measured the resistances between ground and the metal tabs of each coil, then your damaged coil is open circuit.

However, the load on your second coil is indicating that one or more of the ICs are dead. This probably accounts for the heating of the motor controller IC.

As for the 1R2 coil, it is wired to ground, so it is OK. Instead you should have measured the diode to its left. If you measure a short at the diode, when the board is on the drive, then the preamp will be dead, in which case a board swap will be a waste of money.

[Nick_CT]

I think you're leading yourself down a never ending path here. Your understanding of the 'NV-RAM' is incorrect as well.

A PCB would be easy to get, and cheap, from an overseas supplier. Add on shipping, however, and you've already arrived at the price of a new drive. Then you might find that the preamp is gone, so your replacement PCB was for nothing.

Best bet if you want to want to keep playing, is to find another HD154UI in the classifieds, use it's PCB and get Dexter to swap across the patient ROM. There's now a risk to your replacement PCB if the preamp is damaged.

By the time you've finished experimenting I fear you may have thrown away a few hundred bucks.

[online14230]

Ill be first to admit it: Im an idiot.
I have found a replacement board... or at least a board that bears exactly the same parts as mine. Anyway, I took a look at it and then fired up the ol solder station. I moved the choke onto my patient board and then did some additional resistance checking. I recieved very different results from those initial results, which made me quite excited. I replaced the board on the drive and fired it up. The drive spun up and I jumped for joy! Anyway, I plugged it into the walker, attached the USB cable and waitied. The mac picked it up and ALL MY DATA WAS THERE!!
So I started copying... and managed to get a FULL copy of my work folder AND my fathers music! However, as soon as I started copying non critical data (my movies), the drive suddenly ejected itself. I was stunned... until I looked up and saw that my SO had MOVED my coffee closer to me and SPLASHED a little onto the table. This then rolled under the drive...

Now, theres a big black burn mark on the table and Im back to where I started. However, this time, I dont even have any method of powering up the dive to check it since the burn mark was caused by the PS blowing its guts all over the room... Funny enough, the drive itself just switched off and stopped. I found the pins on the power plug wet, which might explain the power supply going poof. Im waiting patiently for a new one...

It seems the HDD is doomed to the dustbin no matter what I do.

For Interests sake, what is the preamp for, what does it do, where would I find it and is it replaceable? Is a clean room necessary for replacement? Just curious...
regards,
MF

[Vulcan]

For Interests sake, what is the preamp for, what does it do, where would I find it

These questions are answered in the following article, written by Doomer <hat tip> from this board:

http://hddscan.com/doc/HDD_from_inside.html

Yes, a cleanroom (or similar) would be needed for replacement, but it's much more complex than this might appear, as the whole HSA would need to be replaced.

[Nick_CT]

[fzabkar]

what is the preamp for, what does it do

It may not help you, but it may help others ...

Datasheets for HDD preamplifiers:
http://www.users.on.net/~fzabkar/HDD/HDD_Preamp.html