PCB fault: 201221500B REV B -Seagate EXOS X20 ST20000NM007D-3DJ103
Hi. I have a damaged PCB on this model, it will not power on. The problem came about after SATA power GND pin 6 came into contact with something (I think) there is some charring between SATA power GND pin 4 & 5. I don't see any other surface damage on the PCB. I have removed GND pin 6 as it was damaged.
I suspect the fault is on a 5V TVS diode or 5V e-fuse. But I need help from more knowledgeable people.
I have measured a whole lot of things with the help of AI, but I have started confusing myself at this point I think. I have not tested with power on, only continuity & resistance. I am a bit cautious to power it up, as the power pin plastic backplane has broken off, the backplane still exists and can be carefully placed in place so a SATA power connector can be inserted, but I would prefer to test as much as possible without power first!
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The conclusion I've come to, but am unsure of: Because the protection switch inside J9 (5V e-fuse) is stuck permanently open, and the rest of the circuit is 100% healthy, bridging J9's input pins (1–3) directly to its output pins (9–11) bypasses the broken internal switch and will safely restore 5V power to the drive.
It would be nice to confirm this. I will follow testing directions.
There is also the component 'K03' near the 5V lines, which I don't know if is relevant, since 'J9' was the 5V e-fuse.
Pictures here:
https://imgur.com/a/AoJw0oy