Samsung 80 GB Desktop SATA HDD PCB Swap

[padmanabha]

Hi All,
I have a Samsung 80 GB HDD which is burnt pcb board of diodes & other service center agent has damaged the pcb board by removing the capacitors at the motor surrounding Smooth IC.
Got a compatiable board of with same PCB board number & version of the hard disk. Donor hdd pcb is in good working condition.
Searched for ROM Chip, it is not available in this old HDD.

Swapped the board without any component swapping. HDD has no detection & gives continuous clicking noise & does not power down even after continuous 3 minutes run.

I Want to resolve the issue with the hard disk & get the data back. Plz sugges the recovery method.

Thanks in advance. Plz find the image of th PCB in the attachment.

Attachments

Samsung Donor PCB of same Model & PCB Board Number

Samsung Patient PCB Board - Damaged

Samsung HDD 80 GB MODEL

[fzabkar]

What symptoms did the patient PCB originally have? Did you measure the resistances of its TVS diodes and zero ohm resistors at the SATA power connector?

BTW, I notice that there is a bent ground pin at the SATA data connector.

Attachments

[padmanabha]

Hi,
TVS Diode 5V has forward 550 Ohms & Reverse 250 Ohms, 5V TVS Diode will burn in another 2 minutes for sure..
PCB has been damaged by other computer service company earlier when client have submitted earlier, they have damaged the board sata pins & removed the zero ohms diodes surrounding to smooth IC & 4 Capacitors are been removed with tracks..

Hence i have searched for similar matching model hdd & working pcb board. Do not know the earlier condition of the drive before pcb damage, client also not sure, just said that it was not getting detected. after swapping the board, the drive has clicking noise. Dont have working head to HSA Swap, wanted to make sure anything can be done for the data recovery...

Thankyou

[fzabkar]

I suspect that the reverse resistance for the TVS diode is coming from elsewhere in the circuit.

As for the "zero ohms diodes", I have no idea what you are referring to. AFAICT there are 3 regulators around the motor controller IC. There appears to be one linear regulator, one positive buck regulator (Vcore ?), and a Cuk regulator for the negative preamp supply. There also appears to be a second linear regulator near the MCU.

Two of the missing capacitors are the output filters for the Vcore and Vio (?) supplies, so it would appear that the previous technician was trying to isolate a short circuit on these rails. If this is the case, and if the short is still present, then this would suggest that the MCU may be dead.

Good luck in finding a compatible PCB. That said, the date codes on the two MCUs are 4 weeks apart (0645 versus 0649), plus the MCU's serial numbers (?) are very close (YSM00696 versus YSM00835). The SDRAMs also differ by only 3 weeks.

I'm wondering whether the preamp's negative supply was damaged.

[padmanabha]

HI,
The circuit board is changed with the same matching model, drive has continuous clicking noise, media level issue. searching for similar donor for head replacement..