Fzabkar, thanks for your reply
As you suggested, I have measured the voltage at resistor R45 where I got a reading of 1.35 V.
Also I have measured all the voltages of the preamp connector J1. For this, I have chosen a screw hole on the PCB as ground. (My multimeter in the DCV scale and selecting 20 V).
Point #1: 0 V --------- Point #2: 0.05 V
Point #3: 3.28 V ------ Point #4: 3.26 V
Point #5: 3.01 V ------ Point #6: 5.09 V
Point #7: 3.01 V ------ Point #8: 2.40 V
Point #9: 0 V --------- Point #10: 0 V
Point #11: 0.10 V ----- Point #12: 0 V
Point #13: 0.10 V ----- Point #14: 0 V
Point #15: 0 V -------- Point #16: 0 V
Point #17: 0 V -------- Point #18: 0 V
Point #19: 0 V -------- Point #20: 3.36 V
Again, I have tried to measure the jumper plug J6.
I have done quite a lot of tests in order for me to try to measure the voltages of the conector pins 1-4 of J6.
And finally, I have been able to measure them well.
After many trials, I have been able to notice the following:
The connector pins of J6 ONLY have a voltage just after plugging the PCB into the SATA power connector of the PSU. And this current in the connector pins of J6 is kept ONLY during 1 minute or so. After which, there is no voltage at all in the 4 connector pins of J6.
I have made a lot of trials and the same thing always happens. Surely, the Smooth motor controller is responsible for this.
Anyway, there is a current on the 4 connector pins of J6 ONLY during the first minute just after the PCB has been plugged into the SATA power connector.
I have also tried to use Power Up in Standby (PUIS) which is a specific HDD feature that allows the drive to spin up only when necessitated by a command, rather than when turning on the computer. It is intended to save energy.
In order to activate PUIS, one must short pins 3-4 of the back port of the drive.
While PUIS was activated, I have been able to verify that there is NO current at all in the connector pins of J6 (not even during the first minute). And when PUIS is disabled (by removing the cap that shorts pins 3-4), there is certainly a current in the 4 connector pins of J6 but ONLY during the first minute.
The voltages I have been able to measure during the first minute in the connector pins of J6 are exactly the following:
A) At Bottom:
I get a reading of 6.25 V on the left pin.
And I get a reading of 4.16 V on the right pin.
[Note: Regarding the right pin, a few times I got a reading of 5.10 V, but only for the shortest time (1 second or so). Really, it almost immediately dropped to 4.10 V].
B) At top:
I get a reading of 7.40 V on the left pin.
And I get a reading of 5.92 V on the right pin.
[Note: For more clarification, see Picture #5 where I have marked the voltages of the preamp connectors of J1 and also I have marked the voltages of the connector pins of J6].
As stated above, after the first minute onwards, there is no current in the 4 connector pins of J6. (That is, there is no current at all most of the time. I can confirm that this is so after many trials).
It is very likely for the Smooth motor controller to be responsible for this.
The following are exactly the voltages I have measured after the first minute onwards:
A) At Bottom:
I get a reading of 0 V on the left pin
And I get a reading of 0 V on the right pin.
B) At top:
I get a reading of 0 V on the left pin.
And I get a reading of 0.12 V on the right pin.
I am thinking about purchasing a new PCB which is compatible with my HDD and later a computer technician would transfer the firmware from my old PCB to the donor PCB. But the problem is that this type of board has no chip at U12. Therefore, the BIOS is embedded in the Marvell MCU chip.
But before buying a new PCB compatible with my HDD, I want to be totally sure that the motor of the HDD is not working badly. In fact, before the HDD got inaccesible, sometimes the HDD did NOT manage to spin up. I think so. Therefore the motor of the HDD may be failing. And in this case, the repair would cost me too much money. I have been quoted a price of 500 EUR (about 800 australian dollars) for this type of repair, here in Spain. It is too much money.
How could I check whether the motor of the hard disk is in good condition (without opening the HDD)?
On the back of the disk, there is a flex ribbon cable with 4 contacts. I have thought about measuring resistance.
Could you tell me what the right values (in ohms) are?
In this way, I would know whether or not the HDD motor is working well.
Because if the the HDD motor were damaged, the repair would cost me too much money.
I have taken a photo of the back of my HDD in order for you to tell me which points I should measure.
Please, see Picture #6 and circle the points I should measure there.
Thank you.
Again, another possible solution could be the following:
A technician in electronics could solder the Marvell MCU chip from the old PCB onto the donor PCB that I would buy in Ebay or another store.
But before doing this, I want to be totally sure that the Marvell MCU of my old PCB is in good condition.
How could I check this?
Which points should I exactly measure?
Thank you.
- Attachments
-
- I have marked all the voltages of J1 and J6 pins in the photo of the PCB.
-
- Back of the HDD where you can see the flex ribbon cable that makes contact between the HDD motor and the jumper plug J6.
-
- The back of my PCB.