Seagate Momentus XT 500GB ST95005620AS TVS diode

[nusch]

Could you please identify the broken element, I guess it's 5V TVS diode? Which what could I replace it ?

[networks]

I see one of them that looks burned up just remove it and give it a try

[fzabkar]

Also measure the resistances of the 3 zero-ohm resistors going to pins 4,5,6 of the SATA power connector.

It goes without saying that you should check the +5V power supply ...

[nusch]

fzabkar, networks, The resistors are ok. I'm also aware I can simply remove the TVS, but then I lose the protection - next power failure will make it unrepairable so I want to replace not remove.

[fzabkar]

I suspect that an SMAJ5.0A should fit.

The diode must be unidirectional, and its rating should be 400W, with a 5V working voltage and a breakdown voltage of around 7V.

Try Farnell:
http://pl.farnell.com/

[Vulcan]

@nusch,

next power failure will make it unrepairable

To be clear, it is not a power failure (i.e. a loss of power) which is the problem. It is a significant +5V overvoltage that is the concern.

In fact even with a TVS, a prolonged overvoltage can still cause damage - if the overvoltage continues for more than a short period, the TVS will likely be destroyed (like yours). Then, depending on the exact behaviour of the power source and the (then damaged) TVS, the device (disk drive etc.) can become badly damaged anyway. You cannot rely on a TVS to save your device! Your Seagate disk could already have suffered from additional damage...

As fzabkar said - you should investigate your power supply, to understand why you had a +5V overvoltage.