Hello,

I have a seagate Momentus 5400.2 disk which is having trouble initializing.
When HDD is powered:
1. Disk spins up
2. Moves head
3. Parks head
4. Spins down

This all happens in 2 a 3 seconds and is repeated until I power it off.
I connected to the terminal interface and the following repeating pattern occurs:
Head Mask FFFF - FInterface task reset
4096k x 16 buffer detected
MERCURY - 1_Disk 3.06 01-19-05 14:20
Head Mask FFFF - FInterface task reset
4096k x 16 buffer detected
MERCURY - 1_Disk 3.06 01-19-05 14:20
Head Mask FFFF - FInterface task reset
4096k x 16 buffer detected
MERCURY - 1_Disk 3.06 01-19-05 14:20
[...etc]


I am expecting something following "Head Mask FFFF - F...", But it appears to reset after that.

Anyone ideas about what could be the issue here or how I can proceed?

Heads issue and possible platter damage.
Stop powering on and seek professional service for an accurate evaluation.

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Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts

Is your opinion based on the symptoms, or the output from the terminal?

Terminal log looks like it would if power were being repeatedly interrupted. Check your wiring and PCB.

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You don't have to backup all of your files, just the ones you want to keep.

Yes looks like some problem with power. Cables, pcb, connections...

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http://www.northwind.gr
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drc and northwind have valid points. I may have jumped the gun a bit, hence I suggested for you to get an accurate evaluation from pro.

_________________
Hard Disk Drive (HDD), Solid State Drive (SSD, SATA, NVMe, etc), USB Flash Drive and RAID Data Recovery Specialist in Massachusetts