Hi, I’m diagnosing a short on the SATA 5V rail in my WD HDD.

The fuse is blown, and one diode (the larger one) is clearly shorted (~12 Ω), while the other (smaller one) is not shorted but shows only 0.14 V forward voltage. Is that expected, or should it be higher?
Am I correct in assuming that both are TVS diodes (one just being more robust than the other)? Why are there two of them instead of a single device?

I wasn’t able to identify them by their markings, even though the larger one appears to be from ST.
The photo below shows the 12V rail, but the power delivery components there are analogous to the 5V rail (the 5V components are currently desoldered, so I’m not including a photo of empty pads).

Thanks!

You have posted to the wrong forum. HddSurgery is a tool supplier.

Anyway, the small diode is a Schottky rectifier. I believe it provides reverse polarity protection.

_________________
A backup a day keeps DR away.

Oh, so sorry. I figured hdd surgery is a funky name for twiddling with hdd hardware internals (hence name surgery).

0.14V is kinda acceptable for a shottky (it might have survived the hit) but id be replacing it anyway.