HDD GURU FORUMS

Hello friends,

we hope you can help us. We tried some ideas from the forums, but we didn't find the right one. Just for info: We have some experience with data recovery and repairs with electronics..

The customer brought us a WD30NMZW-11GX6S1 (Spayglass) USB HDD. The HDD was manufactured Jan. 2017. The PCB Board (2060-800041-003 Rev: P1) is dead.
The white LED did not light up and the disk did not start up. First they looked for defective components (diodes, etc.) and cold solder joints, but nothing was found. No component gets warm under USB voltage. The zero-ohm resistance at the USB port was also checked and re-soldered, there is 5V on both sides. We checked the ROM (U12) and we could read it, so apparently not damaged. Unfortunately, we can't find a circuit diagram for this PCB, so the measurements were roughly compared with an exactly the same donor PCB and found that, for example, the VCC 1.8V on Pin8 was missing in the ROM (U12). Apart from 5V, we couldn't actually measure any other relevant voltages, such as 3.3V or 1.8V.

So we think the problem may be with the internal (5v to 1.8v or 5v to 3.3v) voltage converter.

We soldered the ROM to the donor PCB and the hard drive starts up with it. PC3K also shows as "Ready". PC3K Utility displays the correct model and serial number, but also, the SED encrypts the service area. We still don't get access to it with the donor PCB, because apparently the SED encryption runs via the main processor (MCU) of the original PCB. This encryption is unique. (We have tested the read ROM content with PC3K and shows that it is not SED encrypted)
So we absolutely need to repair the original PCB to get the data decrypted by the original main processor.
We are very grateful for every useful idea or schematic of the PCB.

Check that the 3.3V rail isn't shorted to ground. If it is, look for a shorted MLCC.

The switchmode supplies are all controlled from within the REDFIN motor controller. There are only a few external passive components. If the motor controller is otherwise healthy, you may be able to inject an external 3.3V supply into the PCB (after removing the inductor). You might want to practice this procedure on a donor PCB first, though.

I suspect that the 1.8V supply is derived from the 3.3V supply. You could test this idea by removing the 3.3V inductor on the donor PCB.

If there are no supply voltages present at any of the inductors, then either the REDFIN chip is dead, or it is not receiving a 5V supply.

I suspect that the 1.8V supply is derived from the 3.3V supply.

hoho, this would contradict your statement banning me in this topic:
https://forum.hddguru.com/viewtopic.php ... 87#p297587

pepe wrote:

I suspect that the 1.8V supply is derived from the 3.3V supply.

hoho, this would contradict your statement banning me in this topic:
https://forum.hddguru.com/viewtopic.php ... 87#p297587

I don't know what you mean by "banning", but that was a different case. In that thread you appeared to initially suggest that the entire SSD was powered from a 3.3V supply derived from the 5V supply via a single converter. That would be a bizarre, if not ridiculous, design in a 2.5" SATA SSD.

The present case could be two small cascaded supplies, something like flash drives where the Vio and Vcore supplies are cascaded via LDOs. In fact there was another HDD thread where this same scenario appeared to exist (you were a contributor to that thread). The total current draw of a flash drive is typically much less than 100mA. I guess one reason that a designer would do things this way would be to ensure that the two supplies powered up in the correct sequence.

I was using the word 'cascaded' in that thread so you clearly misunderstood something, yet throwing all the shit over me, while i never said the whole thing runs on a single 3.3V supply, that was your implication. Moreover you declared my idea of cascaded converters a brainfart while now you clearly admit these exist here and there. My attempt to clear up the misunderstanding was honored with a nice post as well.

Sorry Taylor for spamming your thread

about this job, it is being cloned and had a couple of other problems apart from pcb. Since this model is not having MCU-tied encryption, we tossed the bad pcb and worked with a donor.


pepe

It's ok Pepe. No problem.

Both of you just want to help for us, in this case especially for me. In a previous trade you most likely had a big misunderstanding between you.
But I think it's quite normal in our lives that we don't always have the same opinion. Such discourses are sometimes necessary to move forward.

Nevertheless, I am so grateful that there are people like you both, who help other people in their free time.

That's why I want to say a big THANK YOU for both of you.