Hitachi Deskstar - no spin after incorrectly connected power

[sowieso]

The drive does not spin up, makes no sounds at all. Power was connected in reverse (12v <--> 5v line)
I have attached the drive's photos. The PCB looks fine, but on the 5v -> GND the multimeter (diode mode) shows value ~656 , GND -> 5v ~560 ...The 12v line has infinity in one direction and value 135 in the other one.
On the picture is one diode visible. I tried to remove it, but no change - the drive still no spin. Every element looks untouched, so i'm afraid that the inner electronics of the hdd (preamp?) have been damaged by the 12v from power connector.. I dont wanna buy donor PCB if it will not be helpfull in this case :/
Any advice?

Attachments

photo of the drive's PCB

photo of the drive

[fzabkar]

The components at U5 and U6 are both EEPROMs. In current models, you would expect that one or both chips would need to be transferred from patient to donor. Judging by the date codes, your board dates from around July 2003 (which matches the label), so I don't know whether this applies in your case. I'm not a DR guy, so you would need confirmation from others.

In any case, here are the datasheets for the two chips.

L76R, Microwire BUS 8Kbit (512 x 16bit) EEPROM, SOP-8P:
BR93L76RF, Rohm
http://www.rohm.com/products/databook/e ... r93l-e.pdf

AT45DB011B, Atmel, 1-Megabit 2.7V only, Serial DataFlash:
http://www.datasheetcatalog.org/datashe ... 3916_1.pdf
http://www.atmel-grenoble.com/dyn/resou ... oc1984.pdf

As for your concerns regarding a shorted preamp, I believe that the anode (non-striped end) of diode D2 (near the top LH corner) is the negative supply for the preamp. Therefore, I would test the resistance between anode and ground, eg the mounting screw.

I would also test transistors Q1 and Q3 (to the right of the central mounting screw) on the diode range of your DMM.

If you need it, here is the datasheet for Q1 (2SA1242):
http://www.i-t.com/graphics/2sa1242.pdf

Check resistor R5 near the power connector, and also check the zero-ohm resistors, eg R4, R25, R29 (at about 10 o'clock from the central screw).

[sowieso]

I would like to know how to determine the condition of the preamp, Is there a chance that this deathStar would stop spinning just becouse of preamp shorted/damaged ? I will not try to swap the heads, so if pcb swap wont help, it will be waste of money (buying a new pcb) ..But thank You for the hints, i will measure these elements today.

Can i measure pins on hda , similar as in old maxtors, to determine if the preamp is shorted? im trying to figure out which pins, but have no healthy drive to see the difference..

[fzabkar]

A shorted preamp would normally cause the power supply monitoring logic in the motor controller combo chip (U3) to shut down the board, assuming it can tolerate the short. I don't know how this particular chip behaves, though.

I don't know which pins are the preamp supplies, but I believe that the anode of D2 connects to the negative supply pin. The ground pin(s) should be easy to find.