Hi Guys!!

Let´s try to go deeper on this very common hdd issue.

Is it known that the clicking noise is in most cases due to bad heads system or pcb problem. With the heads there is nothing without pro tools. So, lets go to try pcb issues.

Here is my litle contribution on this issue. I had detected in some disks that the 0 ohm resistor of the 5V line had degraded to 10-20 ohms causing a drop in 5V feed.

In other cases i have noticed that when disk clicks the negative -5V flicks, but in this case can not arrive to a good conclusion.

Waiting for your contributions,
Thanks in advance,
Oleg.

P.D Excuseme for the bad english.....

That's very interesting. However, I think you will find that very few, if any, people actually measure anything. Instead they usually just swap boards and move the "ROM".

One observation I have in regard to the -5V supply is that it is usually generated by the motor controller IC and can be switched on and off via a command from the MCU. So if the MCU does not detect the preamp, or if it detects a fault in that area, then it can switch off the -5V supply. It may even do this during standby, but I've never checked this.

If you suspect a problem with the -5V supply, perhaps you could add additional capacitance in parallel with the output cap. I would use a high frequency ceramic cap.

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A backup a day keeps DR away.