Seagate ST2000LM007 PCB (External HDD) troubleshooting

[exmate]

Good Day.
Resently I've dropped my Seagate ST2000LM015 while it being working. It didn't drop to the floor, but just had hang  on the cable. Newertheless it stopped working - just pereodic peeping and no rotation - i.e. most probably heads stuck.

Just for curious purpouse I had swapped it's PCB with  my another ( Working) HDD ST2000LM007. It was stupid idea - now my 2nd LM007 HDD stopped working also with same beeping and also without rotation I have ordered PCB for my ST2000LM007. But now i am thinking-  may be just some fuses or component burned due to overcurrent caused by first HDD motor or head's magnet ? I've cheched Resisotors marked "0" - They are ok. Also I've checked diod - it shown 1.5/0.5 V (but in resistance mode it has "0" in both direction). What also I can check ? BTW - i also have oscilloscope 100mHz. 

Many thanks for any suggestions.

[fzabkar]

I suspect that R332 may be the current sensing resistor for the spindle motor, and R680 may be the current sensing resistor for the voice coil.

Perhaps one of the MOSFETs for the three motor phases has been damaged (inside the motor controller)? You could measure the voltages and resistances at the motor terminals on the PCB and on the motor itself. Measure the phase-to-phase and phase-to-ground resistances.

[exmate]

I suspect that R332 may be the current sensing resistor for the spindle motor, and R680 may be the current sensing resistor for the voice coil.

Perhaps one of the MOSFETs for the three motor phases has been damaged (inside the motor controller)? You could measure the voltages and resistances at the motor terminals on the PCB and on the motor itself. Measure the phase-to-phase and phase-to-ground resistances.

All resistors are ok. Voltages on the motor connected is 5v, see attached . Signal on every motor contact is different.

I am also wondering - why connection to damaged HDD L015 of PCB from L007 made last PCB defective also?
Coils of motors is not short circled with 0.5Moh ... Actually I am mainly curios abt this, and already ordered donor PCBs for both HDD.
Is it possible that head coil if short-circled can damage PCB?
I've received donor PCB for L015, but afraid to connect, as it can become damaged also.

Attachments

[fzabkar]

Unfortunately you have picked one of the worst drives to work on.

ST2000LM007 / ST1000LM035 – Is this the worst HDD ever made?
https://www.cheadledatarecovery.co.uk/2018/02/st2000lm007-st1000lm035-worst-hdd-ever/

It's also an SMR model which makes things potentially a lot harder.

Here is the datasheet for an early SMOOTH motor controller (L7250):

https://pdf.dzsc.com/L72/L7250.pdf

Perhaps it will help you to understand these devices.

BTW, your drive's heads are very flimsy, so if you do manage to overcome the stiction, the sliders may come off the heads and gouge the platters.

[digisupport]

You pcb is 100% working. Heads are stuck on media. On a Rosewood drive, i would say you have no chance to recover data on your own. If data is important, seek professional help.

[pepe]

Even if pcb is replaced (with rom swap), drive won't come alive because of the MCU being not native. It won't respond to commands over SATA interface without further pressure.
So yes, your best chances are with pro help.

pepe

[exmate]

Even if pcb is replaced (with rom swap), drive won't come alive because of the MCU being not native.

You mean that Ive damaged my lm007 PCB by connecting it to faulty Hdd lm015 and now i wont make lm007 to work even if i get working PCB from 007 and swap BIOS? Then it is problem... Have you any idea what can be burned on LM007 PCB by connected to fault LM015 HDD ? Are you sure that MCU has drive specific firmware on Seagate lm007 ? You make me dissapoined My superficial knowledge very often leads to damage

[exmate]

You pcb is 100% working. Heads are stuck on media. On a Rosewood drive, i would say you have no chance to recover data on your own. If data is important, seek professional help.

Well, LM007 was 100% working . After I've connected its PCB to LM015 it become damaged. When i connected it back to LM007 - there is same symptoms and similar waveforms on motors as on lm015 (which i dropped). Heads on LM007 was 100% in parking position on beginning of PCB swapping. I hope i've just burned something on 007 PCB while connected it to LM015 and now waiting for the donor's one...

[SirForensic]

Based on the description and seen information the PCB is fine. You have a mechanical issue there, the heads are most likely stuck on the platters, and you need professional help.

Opening it in a non-cleanroom environment and trying to do things by yourself might cause even more damage, and it will cost you more money. Sometimes the heads are still usable after releasing them by the professional.