Seagate Baracuda 2000GB not detected !

[begmz]

Hi all, first of all let me explain myself. I am really very old this lockdown is very frustrating for me. So I got involved in Electronics, and got some hard drives which belong to my son which are not working. So I thought why not try to repair them
and learn some thing etc. etc.
I have measured voltages of some components, I think one of the mosfet is not working. I am not sure though. You please have a look and let me know what you think. If you want me to measure more points, please let me know. I am attaching a photo of it. Thanks

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[unknown]

PCB looks fine, what's the drive problem?
Is it spin up ?

[fzabkar]

C-4 is part of the -5V supply for the preamp. I believe this supply voltage should be present at pin 2 or 4 of the HDA pads (opposite PIN-1).

[begmz]

Yes it is spinning. I will check pin 2 and 4.

[unknown]

Yes it is spinning.

Then the problem elsewhere.

[begmz]

C-4 is part of the -5V supply for the preamp. I believe this supply voltage should be present at pin 2 or 4 of the HDA pads (opposite PIN-1).

Additional readings found on HDA pads. Pin 11 is +4.93, hope this help.

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[pcimage]

If it’s spinning then it’s 99.99% nothing to do with the PCB.

[fzabkar]

The way you appear to be counting the pins is 1 to 9 along the top row, and then 10 to 18 along the bottom. I count them as 1-3-5-7-9-11-13-15-17 along the top row and 2-4-6-8-10-12-14-16-18 along the bottom.

You haven't measured the -5V supply, but this supply is often turned on briefly before being shut down when the MCU fails to detect a preamp. In any case it's most probably not a PCB fault.