WDC WD40NMZW-11GX6S1 spyglass does not want to spin up

[osity]

Changed heads, installed an unlocked SATA PCB and the drive initialised and gave full ID but then spun down after just seconds and it did not want to spin back up regardless of any RAM head mapping.
If my understanding is correct, this family does not like RAM headmaps. Is this correct? I tried anyway and there was no change in behaviour.

There's no attempt at spinning up anymore unless I repower the drive but then its a only a very short spinup with no init attempt or seeking of heads whatsoever and it spins down within 2 seconds.
Is the drive pre checking all heads and finding a problem that prevents spinup on this model?

Any assistance is appreciated!

[d_d_recovery]

Source of the post Is the drive pre checking all heads and finding a problem that prevents spinup on this model?

Yes it is.
WD SMR drive complete a head check (tests resistance) when booting up.
If that test fails the drive will spin down.
Sounds like your drive has media damage which is killing the heads.
You might want to put the donor head back in the donor and see if it still spins up that drive.

[Hary]

According to my researches, the head test You guys have mention about is performed for each head separately, so if You modify head map in ROM module 0A and manage to switch off broken head, drive should spin up again

[anekakeck]

Hi

Check you didn't give the drive stiction, or try another SATA PCB. If it's not stiction it's likely a preamp issue. But eliminate a faulty PCB first, if you dont have another SATA PCB try the original USB to see if this freely spins the disk.. I've worked on several of these when this has happened.

Thanks

[Hary]

Source of the post Hi

Check you didn't give the drive stiction, or try another SATA PCB. If it's not stiction it's likely a preamp issue. But eliminate a faulty PCB first, if you dont have another SATA PCB try the original USB to see if this freely spins the disk.. I've worked on several of these when this has happened.

Thanks

Sorry anekakeck, You can apply Your way of thinking to an older drive series. By the way, this topic was started 7 months ago had no working solution and that is why I decided to share quite usefull information about modification of head map which works well for SMR drives with head precheck procedure implemented in FW, for example in Spyglass or VeniceR series and this can be helpful even for advanced users who can be suprised that in case of those series ( SMR drives ) normal procedure of finding cause of no spin simply does not work . Drive will just abandon spin after power on even if preamp is good and PCB has no issue. Fail of preeliminary check of even one head will stop drive spining up. But if You switch off the head that has fail the test discussed by osity and d_d_recovery, the SMR drive will magicaly spin up again

[anekakeck]

That's good to know! Generally if you have a failing head i would rather switch out the heads and not cause further damage.. but that's a useful trick there! Yes sorry i realized the date once i replied