Samsung Spinpoint power input circuit

[fantrace]

Bit of a disaster. Connecting up an external sata Samsung Spinpoint 500G disk, thinking that the power was off, but it wasn't. Managed to try putting in the Molex power plug into the socket backwards and shouldn't really be possible, but 12V was connected momentarilly to the 5V input of the drive.

A component in the power input circuit has burnt out (smoke) - its a 1206 SMD, but I can't tell what it was. If there's any chance that this part has protected the rest of the drive so that it will work if I replace it then I'd like to do so. Is there anywhere I can get hold of the schematic circuit diagram for this HD so that I can see what to replace. Model number is HD501LJ. Thanks.

 

[13thmonkey]

is it a surface mount device? you'll not be able to replace it. buying a second hand spinpoint might let you swap the boards over, but you'll be to be careful of the firmware. Mentally prepare yourself for this to be a loss, and be happy if you pull it back.

 

[fantrace]

Yes. Surface mount. I've looked more closely now and I can see a crack along the side of a second device which is a GE R503. Can't find a datasheet for this but I have found a suggestion that it is a TVS device. It measures s/c across it so that would make sense as a protection on the input with a fusible resistor in series to the TVS down to ground. An overvoltage would cause the TVS to short out which would cause the fusible resistor to blow open. If I remove the TVS and short across the fuse it should work (without any protection).

 

[13thmonkey]

Yes. Surface mount. I've looked more closely now and I can see a crack along the side of a second device which is a GE R503. Can't find a datasheet for this but I have found a suggestion that it is a TVS device. It measures s/c across it so that would make sense as a protection on the input with a fusible resistor in series to the TVS down to ground. An overvoltage would cause the TVS to short out which would cause the fusible resistor to blow open. If I remove the TVS and short across the fuse it should work (without any protection).

Might work for long enough to get the data off, might do more damage. As the saying goes, do you feel lucky punk?

 

[fantrace]

The big risk I can see is if it is not a fuse - TVS, but in fact a resistor - zener to regulate the voltage from 5V to 3.3V or something like that. 5V is rated at 0.7A so a regulator is unlikely using a 1206 resistor but that's why I'd like to see the schematic diagram to be sure. I shall hold back from doing anything until I can at least find a datasheet for this GE R503 device which will give a big clue as to whether it is regulating or protecting.