ground to V1 - 10.2
ground to V2 - 143
ground to Vneg - 116.2

Also i have attached an image of the requested area.

I presume V1 is Vcore, which would account for the low resistance. Otherwise, I can't see anything out of the ordinary. ISTM that the motor controller is dead.

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A backup a day keeps DR away.

The V1 V2 is exactly the way you have them in your schematic so yeah Vcore and Vio respectively.

Is there anything that can be done for that? I am aware that changing the pcb for samsung does not work out of the box...

Thanks again for troubleshooting with me and going step by step with patience. You have been really helpful and aside from the disk I learned a couple more things here !

Cheers !

I'm not a DR pro, so I can't advise on board matching. However, if the following thread is any guide, then the "pros" don't seem to know much either.

samsung-hm500ji-pcb-swap-t18471.html

FWIW, I'd take a punt on a straight board swap.

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A backup a day keeps DR away.

This is why I don't want the pcb sent with the drive for recovery, just if the customer really want it repaired too and MCU is not totally fried... but you know, everything has a price !!

Measure the resistance between SDRAM pin #1 and each of V1 and V2. The one that shows 0 ohms will be the Vio supply.

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A backup a day keeps DR away.

Yeah, right. :roll:

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A backup a day keeps DR away.

Maybe my comment is late, But thanks to all your comments I recovered a samsung hd502hj/b, I got a samsung hdj502hj/B01
and use the complete board tor eplace the bad one for the new one, I juts replaced the rom chip, and the hard disk worked fine like new, I made 3 experiments and the result were 2 damaged board, the main bad thingas was that with the pc turned off I used to connect the Hd and then I turned on the pc so the bios made a check of the board id and comparing the id with the info located in the rom chip and the data in the plate area were different so the disk stop working again and the borad got damaged again maybe for a programming included in the main rom, so after 2 new hd I decide to make the last try but inserting the hd only when the pc is turned on and inside windows remember the sata device are like usb so they are plug and play, the system detect the hd not the bios so there is no comunication between bios pc and rom hd, then the hd appeared as f and g and the folder start appearind one by one like magic thing but slowly, so I think the rom took all the info inside the disk and declared as good and original rewriting something inside on the main rom of the hd, and then I made a backu of all the need it info, I turned off the pc and then turned on with the hd conected and the bios detected the Hd normally and the acces to the hd was great like new. I hope this could help someone like it did it to me. by ht way in the picture of the bad old Board, the red lines meand diodes in short circuit

Hi.
Due my stupidity, I was connect power supply to HD154UI reversible >> 12V to 3V pins and 3V to 12V pins. Don`t ask me why. This is long story .
HDD is now dead, no spin. I thing that gone FUSE or diode TVS 3V. Right? Can I simple short-circuits on place TVS 3V? Thanx.

@peyrak, your situation is very similar to Mort777 in the following thread:

http://forums.seagate.com/t5/Other-Exte ... 935#M16176

I confess that I don't understand how an "undervoltage" could kill the drive. You will probably find that your TVS diodes are OK.

The simplest solution may be for you to replace the board and transfer the serial flash memory chip, if necessary.

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A backup a day keeps DR away.

since August 14th, 2012, 16:11 till nov 17 2013 the Hd is still working fine with no bad sectors in the test with hdd regenerator, so one year after the mainboard replaced things are fine!

Thank you very much, for posting URL to Seagate forum, whre your answer is exactly what I expect "Unless the USB-SATA bridge board has taken the hit, the most likely problem is a shorted 12V TVS diode near the SATA power connector on the drive's PCB. If the damage is confined to this protection diode, then it can simply be removed by snipping its pins with flush cutters. Your drive will work without it, but it will no longer have any overvoltage protection on the 12V rail. So be absolutely sure your PSU is OK"
But, my english is zero, I don`t be able translate to my language this: "then it can simply be removed by snipping its pins with flush cutters." can you describe it, please? Or my important question is, shorten (damaged) TVS diode (12/5v) i have to : A.)remove or B.)connect (bridge) its both pins with wire? thanx.
If TVS is TRANSIL, that after accident it will be shorten and i have to replace FUSE also ?

That thread began with a Seagate drive that had sustained an overvoltage on the 12V supply. Your problem is completely different. The reason I referred you to that thread was that it had been hijacked by Mort77 who introduced a Samsung drive with the same scenario as yours. As in his case, your TVS diodes are probably OK. I suggest you perform the same measurements as Mort77 just to confirm that you indeed have the same problem. I can't offer a solution at the moment, but it might be worth watching the Seagate thread in case there are new developments.

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A backup a day keeps DR away.

My harddrive is back. Alive. Fuse was interrupten only. No other damages.