Component Identification Request

[LDSisHere]

Hello,

I am trying to revive a Seagate hard drive and I am having trouble identifying a part on the board. The component I need help with has a red arrow pointing at it in the first picture. The second picture is of the whole board for reference.

I am thinking the component is a diode, but with no silkscreen and it being white I am in doubt. Any help in this matter would be very much appreciated.

Thanks!

[SteveNielsen]

Re: Component Identification Request

I am guessing that it is a zener diode from the BZ marking but without the the number can't guess the specifics about it.

[redwire]

Re: Component Identification Request

The white ceramic, odd ball size (not 1206) and non-symmetrical end leads make it a strange part. My guess is a SMD chip fuse. I tried looking at Littelfuse, Bourns but nothing is an exact match.

[budm]

Re: Component Identification Request

What resistance reading do you get when using Ohm mode, in Diode mode?

[stj]

Re: Component Identification Request

it's a crystal or resonator.
atleast it looks like one - trace the connections.

[noppa]

Re: Component Identification Request

It's a Shock Sensor.

What's the problem with your HD?

[redwire]

Re: Component Identification Request

Wow I was totally wrong about that part. My HDD knows when I bump it... It seems to be a muRata (Piezotite) shock sensor (pdf), they generate ~1-2mV/G.

That HDD pcb has a lot of black vias and others gold. A problem with oxidization and corrosion?

[LDSisHere]

Re: Component Identification Request

Noppa, after much Google searching I found some information agreeing with your conclusion that the part in question is a shock sensor.

I do not recall my meter readings when probing this part, however when I was checking for unusual shorts and opens this part did not read like a diode so I wanted to know what it was if not a diode.

As far as the drive goes, it stopped spinning. The motor windings test good but the board is not putting out a square wave to drive it, just a flat 6.xxV. (Checked with my scope.) The main (biggest) chip gets quite warm pretty fast also, way more so than the Seagate drive I was using for comparison purposes.

The drives owner agreed to try a donor board, so I found one that came off an identical drive that was made at nearly the same time. Once it arrives I will of course move the EEPROM from the original board to the donor board before attempting to test it.

I want to say thanks to everyone for their input and trying to help identify the mystery part. I know I have learned something new and hopefully I am not the only one. Surface mount parts can be a real pain to identify so I like it when I can add information like this to my internal inventory.

I will report back it the donor board swap was successful or not, as I understand there is a good chance it will fail.