Samsung HS122JF - Where is the transient voltage suppresor?

[crobison]

I have a Samsung HS122JF that on my Deepspar comes un with a BSY, DSY, DSC and UNC, I went through and checked the chip I thought might be the TVS and when I use the voltameter to check it there is no continuity. The chip is the wAN7, can anybody confirm this chip as the TVS?

Thank you..

[CK]

What about thru a normal power supply, does the drive spin?

[fzabkar]

Does it have a polarity stripe?

Is it connected across the supply?

Can we see a detailed photo?

[crobison]

I connected straight to the power supply bypassing the deepspar, but same... You want a detailed photo? The pcb board? I will load it up... This drive is extremely difficult to detect if it´s spinning, I think I will need a stethoscope...

[CK]

Try your ear

[drc]

If you're using a half decent power supply, connecting a drive with a blown TVS should cause it to shut off

[fzabkar]

If you're using a half decent power supply, connecting a drive with a blown TVS should cause it to shut off

The OP said the component measured open. It's an unlikely failure mode for a TVS diode, but not impossible.

[crobison]

Photo of PCB, the circled chip is the chip that does not show continuity. Is this the TVS?

Attachments

[crobison]

Try your ear

Turned everything off, tried the ear theory, don´t hear anything..

[itconcept]

Try to connect other similar PCB if drive spins it means your PCB has Problem if same condition "Head stuck in side" u have to open and see.

[crobison]

Try to connect other similar PCB if drive spins it means your PCB has Problem if same condition "Head stuck in side" u have to open and see.

Unfortunately I don´t have a similar board, but how about the chip that has no continuity?

[drc]

The OP said the component measured open. It's an unlikely failure mode for a TVS diode, but not impossible.

If it is open, how has it failed in a way that will affect the circuit?

[crobison]

The OP said the component measured open. It's an unlikely failure mode for a TVS diode, but not impossible.

If it is open, how has it failed in a way that will affect the circuit?

The drive is not spinning up, I think that it could be a fuse (TVS Diode) which needs to be removed, so that the drive can spin up? The laptop was working, got moved to a location near by and presto the drive would not come up..

[crobison]

The OP said the component measured open. It's an unlikely failure mode for a TVS diode, but not impossible.

If it is open, how has it failed in a way that will affect the circuit?

The drive is not spinning up, I think that it could be a fuse (TVS Diode) which needs to be removed, so that the drive can spin up? The laptop was working, got moved to a location near by and presto the drive would not come up..

Now generally the fuse is on the side where the power connects to the PCB, but in this case the only chip without any continuity is on the other side of the pcb board..

[BlackST]

Ray Charles and Stevie Wonder are back to back on a dark street... "Hi, Ray !" "Hi, Stevie !"

[fzabkar]

The OP said the component measured open. It's an unlikely failure mode for a TVS diode, but not impossible.

If it is open, how has it failed in a way that will affect the circuit?

It won't affect the circuit, but it will give an indication as to what killed the drive.

In any case, the OP was asking for help in identifying the component, whatever it is.

[fzabkar]

The photo is not very clear, but there appear to be two components with that same marking. Therefore I doubt that either is a TVS diode, at least not ones that are connected across the supply.

Does the other part measure open as well? What are those two horizontal devices directly below? AFAICT, they seem to be associated with the spindle motor circuit.

[fzabkar]

I suspect that there are actually four "wAN7" components, not two. I'm wondering whether they constitute a full wave bridge rectifier to derive emergency retract power from the motor windings after power loss.

[crobison]

I suspect that there are actually four "wAN7" components, not two. I'm wondering whether they constitute a full wave bridge rectifier to derive emergency retract power from the motor windings after power loss.

Correct there are 4, but only 1 does not show continuity.. The one circle in red shows not continuity..

[fzabkar]

I suspect that there are actually four "wAN7" components, not two. I'm wondering whether they constitute a full wave bridge rectifier to derive emergency retract power from the motor windings after power loss.

Correct there are 4, but only 1 does not show continuity.. The one circle in red shows not continuity..

Perhaps you have a stiction issue. Maybe an unsuccessful emergency retract left the heads on the platter(s)???