Dead 1tb WD1001FALS drives

2 drives bit the dust this week. Both are the Caviar Black 1.0tb WD 1001FALS drives. Both were in an external USB case that supports up to 2tbs. I originally thought the case was bad so I ordered a new one. No Go. Took the drives out and attached one to an internal SATA controller - Bios will not pull up the info from  either drive and the WD drive checking software says no wd drives found - error 201 - Other software like testdisk will not locate either drive. On my windows 7 laptop each drive needs to be initialized but shows 0bytes and will not let me initialize either drive. So here I am a year after these drives were purchased and they were fried by lord knows whatever. The external case is fine - power supply is fine - have tried 2 cases an external SATA to USB and internal controllers - so my only conclusion is this. Sounds like neither drive is spinning up - I can hear a power on sequence but no spin up and if you hold the drive no centrifical forces. What is the next step to check these drives before I RMA them. They actually contain 600gigs each roughly of professional video data files and editing that I may or may not be able to duplicate.

I have read several posts about the  power boards being replaced or at least checked to see if the board is functional. Don’t want to void a warrenty at this juncture. Any help here would be welcome!

You need Master DOS version 7.0 or DOS version 8.0 for fix that problemo or fix the MBR first.

Humm - and what would  the DOS 7 or 8 do to fix the MBR - especially if the drives are not spinning up.

Further - these are not boot drives - only used for storage. When they show up in BIOS - there is no info about either drive - no description at all just that there is a drive attached.

If both drives failed at the same time while in the same enclosure, then I would suspect a power issue, ie an overvoltage. If so, then check the SMOOTH motor controller for burn marks, and check diodes D3 and D4, and resistors R67 and R64, located near the SATA power connector.

Measure the resistances of the diodes and resistors using a multimeter set to the 200 ohms range.

A straight board swap probably won’t work because the Marvell MCU (big “M”) stores unique, drive specific calibration data. These data would need to be transferred to the donor.

1 Like

Initial findings on 1 board -

No obvious burns or smell of a burn out - The soft pad covering underneath has no burns on it either.

R64 reads .5

R67 reads .5

D3  reading does not move - stays at 1

D4 same as D3

What do these readings really tell us?

I’m assuming that the “1” readings are indicating “overrange”, in which case all 4 components are OK. If you would like to take some additional measurements, then upload a detailed photo of your board.

I will do that later today - and as a side note - I purchased another WD 1001FALS and am formatting it today. It spins up perfectly and I can tell the immediate difference.


My meter starts at 1 - so the ohms reading never moves from the 1. I assume that means 0 resistance.

That isn’t “0” resistance, it’s INFINITE resistance.  Anyway, when checking a diode you have to also REVERSE the lead’s polarity, so you can test for leakage.  However, you would have to know the circuit to see if you can test a diode that is “in circuit”.

I hope the picture provides enough info.

The photo is very poor. :frowning:

Anyway, I would power up your board on its own and measure the voltages at pins 2,4,6 of the 20-pin preamp connector, J1. These will be the +5V and -5V supplies for the preamp. Use the SATA power ground as your 0V reference, ie connect your black probe to ground. Be careful – a slip of the probe may cause major damage.

Also measure the voltages on the metal tab and end pins of transistor Q1 underneath the SDRAM chip (U2). This is probably the pass transistor for a 3.3V or 2.5V linear regulator.

Now measure pin 8 of U12, ie the vacant location under the MCU (U5). This is reserved for a serial flash memory. Pin 8 is the rightmost of the 4 pins nearest the SATA connector.

There will be two more supplies, the Vcore for the MCU (1.2V ?), and the 2.5V or 3.3V supply for the SDRAM and MCU Vio. These will be generated by the switchmode DC-DC converters under the SMOOTH chip. Measure the voltages at the two leftmost inductors (Lx). The rightmost inductor is part of the negative supply for the preamp. The -5V supply should be present at the anode (non-striped end) of diode D2.

BTW, the TVS diodes are connected directly across the supply, so any leakage will not affect the drive’s operation. All you need to know is whether or not either diode is shorted.

1 Like