September 24th, 2021, 16:41
fzabkar wrote:pepe wrote:I would hazard a guess that only 0.1% of DR shops have a lab supply.
you have very bad oppinion about DR companies, but we knew that Numbers are not that bad i think. (I have 3 just to make them nicer
I do think he has one, but let's see.
Polyswitch is ok of course, if you have one handy, but you still need to source 3.3V from somewhere...
Btw, i haven't ever seen a PSU that has 3.3V on SATA power connector, which does not mean they do not exist, just they are not frequent. I think there are more Lab supplies in DR companies than such pc PSUs.
The first post in this thread is typical of DR companies. Clearly the OP has no real experience in electronic troubleshooting. If the customer has reported an overvoltage event, then you start with the protection devices and power supplies. I have written detailed tutorials on the subject, and have also provided a quick-and-dirty explanation, yet people still don't get it, even after hundreds of posts. What use is a lab PSU to people who have no basic understanding, other than to impress clients? You and I can locate the power supplies on unfamiliar PCBs in a matter of seconds by visual inspection. It's not that hard, is it?
I would suggest that people spend some time and learn about the subject. They owe it to their customers. Louis Rossman has written a primer on electronic troubleshooting. That would be a good start.
As for PSUs with 3.3V on the SATA cable, I see them all the time in the user forums. People are often reporting that a new drive drive won't spin up. That's because there is 3.3V on the Power Disable pin.
September 24th, 2021, 19:12
September 25th, 2021, 4:35
fzabkar wrote:I'm watching a thread in another professional forum where someone, who is equipped with PC3K and Atola forensic tools, is asking where to find the ROM on a WD PCB (U12), and whether this ROM needs to be transferred to the donor. So tools are one thing, but knowing what to do with them is another. Assuming there is no NAND fault, I could troubleshoot and repair your drive with a $5 multimeter, a short length of wire, and a soldering iron. And it's not because I have any special insight, I'm just applying basic principles.
In your case there is no logical flow in your approach. Any chip level technician who has worked on microcontroller based devices understands that there are 3 primary things to check -- the power supplies, oscillator and reset pin. You don't start by examining the tiny capacitors and resistors (BTW, those tiny black components are usually resistors). These days most electronic devices, including smartphones, HDDs, motherboards and TVs, have switchmode step-down DC-DC converters. The 3 landmarks which identify these power supplies are a piece of silicon, an inductor and one or more capacitors. The silicon component sends pulses into the inductor, and the capacitor smooths these pulses to produce a flat DC output. The output voltage appears at the junction of the inductor and capacitor(s). Look for the inductors and you've found the supplies. It's as simple as that.
http://www.hddoracle.com/viewtopic.php?f=59&t=231
September 25th, 2021, 4:36
September 25th, 2021, 5:31
fzabkar wrote:
I would suggest that people spend some time and learn about the subject. They owe it to their customers. Louis Rossman has written a primer on electronic troubleshooting. That would be a good start.
September 25th, 2021, 5:34
September 25th, 2021, 5:46
September 26th, 2021, 1:02
Arch Stanton wrote:fzabkar wrote:
I would suggest that people spend some time and learn about the subject. They owe it to their customers. Louis Rossman has written a primer on electronic troubleshooting. That would be a good start.
This? https://docs.google.com/presentation/d/ ... 3_143_1135
September 26th, 2021, 5:35
I'm about out of ideas other than just blindly blaming the nand. I might bridge the 3.3 back to the other pad in case it's needed anywhere else but I doubt it. Needs the experience of a Senior member of Ace support I think, I be wary of just swapping PCB'ssuricate.ch wrote:Line to ground = 210 Ohm.
When connected (PCB on HDD), PCB takes 0.045 from PSU.
September 26th, 2021, 15:41
September 27th, 2021, 3:35
October 4th, 2021, 4:23
October 4th, 2021, 14:30
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