SOS HDT722525DLA380 stopped spinning

[avecvous9]

Hello everybody,
Yesterday, my HDD stopped spinning. I think, I am not sure, that a shortcut circuit with the desktop case happened while the HDD was running. Apparently, there is no sign of burn.
First, I cleaned up the PCB and checked the voltage at J3 (input voltage for the motor) = 0v.
At this moment, I replaced the PCB with another working hitachi family (not the same family) the motor did spin (=>the problem is not the motor).
I don't want to try hotswap and nvram resoldering for now, I just want to leave it as my last resort.
Any suggestions, schematics ,partial or full support, are welcomed. Thank you.
P.S.: The picture of the pcb is attached

Attachments

[fabianf]

HI,

u can check with a multimeter if D2 is okay

best regards
Fabian

Attachments

d2.PNG (155.74 KiB) Viewed 8708 times

[avecvous9]

Thank you fabianf for you quick response.
The D2 is good, I checked. However R9 resistance is short-circuited. Do I just need to replace R9 only or check something else before running the HDD on?
Best regards.

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02.jpg (47.58 KiB) Viewed 8698 times

[fzabkar]

I would measure the voltages at transistors Q1, Q2, Q3, and coil L3.

Compare the resistance of R9 against your working board.

[avecvous9]

hi,
R9 has been changed successfully,it was broken, but the HDD is still not spinning.
As requested, the voltage of Q1, Q2, Q3 are as follow:
Q1 1=2.56 2=1.54 3=3.29
Q2 1=3.97 2=5.29 3=3.29
Q3 1=3.29 2=1.58 3=2.60
I pray to god it will not be the IC motor, my live depend on that HDD.
Best regards.

Attachments

Q3.jpg (44.86 KiB) Viewed 8624 times

Q2.jpg (45.01 KiB) Viewed 8624 times

Q1.jpg (36.07 KiB) Viewed 8624 times

[avecvous9]

I forgot to mention L3 voltage, it is 5.31v

[fzabkar]

It looks like the Vcore and Vio voltages (1.6V, 2.6V, 3.3V) are present.

I should have asked for the L1 coil as well. L1 and L3 constitute a Cuk regulator which supplies -5V to the preamp. Do you measure -5V at L1?

Other than those measurements, I don't see what else you could do other than measure the resistances of the zero-ohm resistors and the two 4R7 resistors below the MCU, plus L4 and L2. There is also R5 (R47) near the lower 100uH coil.

[data-medics]

You can forget about hotswap, need to transfer NV-RAM and problem will be solved.

Just use a good hot air smd rework station and wet the contacts with some flux.

[avecvous9]

here are the measurements:
L1 = -3.03v
4R7= 0,8 ohm
L2 and L4 = 0,8 ohm
R5 (R47) = 1 ohm

[avecvous9]

I just want to add
I don't think the measurement I took of the resistors above are 100% accurate. These resistors are typically 10–50 mΩ. My multimeter is not equiped with mΩ function.
All I can tell, I checked with a continuity test and they all gave a positive results including the coils L1 and L4.

[avecvous9]

Right now I am thinking about PCB swap+Nvram resoldering data-medics, do you think it is a guaranteed method? and what are my chances to get my data back? it sound too easy that I am afraid to apply it. I am afraid also to give my self false hopes.

[fzabkar]

Everything looks OK to me. The resistance measurements would be affected by the resistance of the meter leads.

If the NVRAM is OK, then ISTM that a PCB swap and chip transfer would be your next logical step.

Best of luck.

[avecvous9]

A mere 'thank you' is not sufficient to express my incredulous appreciation to fzabkar,