Hello everyone,

I'm struggling with an external HDD drive: a LaCie BiggerDisk 1TB.
First issue: when the drive powers up, the 4 internal HDD start in sequence and one of them starts spinning up, then spins down, and re attempt to spin up, ... It sometimes requires 3 to 4 restart till the 4 HDD are spinning.
At this stage, the enclosure is not connected to the computer.

This has happen many times, and by switching OFF then ON the entire enclosure, I most of the time ended with a working external drive (sadly, not always ...).

The second issue is rather new: now, once all drives are spinning (blue led steady), as soon as both ends of the Firewire cable are connected, one of the internal HDD spins down, then spins up again and the entire drive is no longer usable: it remains detected and available in Windows, but if I try to access the disk, this will either crash explorer.exe or Windows will tell me that the device is no longer accessible. I need to unplug the enclosure from the computer, then to power down the entire enclosure is I want Windows to see the external HDD again.

To me, these spins down then up could be due to a lack of power from the power supply.
ISTM that LaCie has never provided very robust external power supplies. So for the time being, the enclosure is powered by an old ATX power supply.

I entirely took appart the unit, took all components on a flat surface and try to power the unit as such.
Not much of a success sadly.
I tried many (stupid ?) things like swapping the power cables from drive to drive, swapping the ribbons (while making sure that HDD place in the RAID array would remain the same).

Still no luck.

I tried to clean contacts with a specialized spray to remove any dust, dirtiness or oxidization, ...

And finally, the external disk would start normally and be used as usual in Windows. But I don't even understand why.

I took everything back into the enclosure and ... the external drive fails again !

Any suggestions please ?
ISTM that the unit can control the power supply of each drive.
I'm tempted to bypass these power controls and feed each drive directly from the power supply, just to make sure that the transistors in the power supply control circuit are not cutting too much power to the drives.
Does it sound stupid ?

Sorry for this long post, I tried to be as much complete as I could to describe the issues. Feel free to ask questions.

The content of the drive is not really important, but of course, I'd prefer avoiding the loss of these data.

Thank you for your help.

One additional information: I noticed that one of the 2 ribbons has a small dmage (I'll try to post pictures later).
Do you think this can cause the failure of the drives ?
Curiously, knowing that :
- ribbon 1 connects drive 1 & 2, and ribbon 2 connects drive 3 & 4
- the damage is on ribbon 1, but it is drive 4 that spins down then up.
So I'm unsure of the damage of ribbon 1 is the real origin of the problem.

I tried to change the ribbon, but I do not have any 80 pins ribbon left.
I tried with 40 pins ribbons.

The unit would start and get connected to the computer. But Windows would ask me to format the drive as if it was brand new.
I reverted to the original 80 pins ribbons and got my external drive back and running in Windows ... Till I powered down then up the enclosure

I think that most forum members here have never tried to repair or even disassemble this Lacie. Frequently we don't even see the whole unit, as getting just the drives only. So I'd suggest you to ask on user forums, probably someone has faced this issue already.

At the same time be sure to resolve everything with the unit before using it as a production storage. If my memory serves me right, this device is rather old and has unexpectedly noisy fans. And if I recall correctly, it uses doubled RAID 0 as a storage scheme, so you have no redundancy to tolerate any failure.

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@slash14, if you can upload detailed photos of the PCBs, I could help you identify the components and test points.

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Thanks for your help fzabkar.
I'll try to post pictures as soon as I find time to take the unit appart and take a few pictures.

I've always been convinced (but I might be wrong) that the failures were due some way or another to power supply (many LaCie have had this kind of troubles).
One thing is for sure: today, I tried to power the unit from a bench power supply.
The main advantage of a bench power supply is that I can set the output voltage and measure the current directly.
And guess what, the unit drains A LOT of power when the 4 HDD start to spin, even when they're starting in sequence. Up to 3.8A on 12V !
This test tends to confirm that there is definitely an issue with power: the original power supply is meant to deliver 2A on 5V and 2.2A on 12V, I guess at steady state and probably a bit more Amp during transients.

But as far as I can read from my bench power supply:
- at startup, spinning the drives up takes up to 3.8A. Even my ATX power supply had some difficulties to deliver that amount of current. This is probably due to the fact that drives getting older, they tend to require a bit more power.
- at steady state, the unit consumes a bit more than 2A on 5V rail. I'm pretty sure the original power supply, as well as my ATX PSU can deliver this current, but regarding the original PSU, it means that this latter works to its max current output all the times, which is not great as it will lead to wear the components faster.
- not surprisingly, if I want the unit to power up properly, I need to give a little extra voltage to the PSU: at 12/5V and no current limit, the unit sometimes fail to start at the first time. But if I use 12.6/5.5V and no current limit, the unit starts fine.

My hypothesis: the drives are getting older and sucks more power from the PSU.
Because the PSU has always been a bit short on power delivery, and because it has always been used up to its limit, I think that the only way to keep this unit working would be to find a beefier PSU.

With your experience on HDD, do you confirm that HDD tends to consume more power as they're getting older ?

@dmitri: you're completely right about the things you said regarding my unit.
As I said before, this unit does not contain data of much importance, and is used for personal purpose only. I'm sometimes a bit short on data storage on my personnal computer, so this unit can be of some good assistance (even though its performances are not of the highest, and mostly due to the fact that its compatibility with Win7 is not that great, even with legacy drivers)
I simply need to find the root cause of the issue, to make sure that any time I need it, I won't spend hours or days to make it start

I don't have any relevant experience in this regard.

Some product manuals, eg Seagate's, have startup current oscillograms. Most manuals and some datasheets will specify the power draw during various conditions including spin-up, idle, standby, read/write/seek.

BTW, here is a power control arrangement that is implemented in at least some Seagate and WD USB-SATA bridge PCBs.

_________________
A backup a day keeps DR away.

Thanks for your reply fzabkar.

My PCB has indeed the same kind of power control management circuit, actually two of these per HDD: one for +5VDC, the other for +12VDC.
I'll spot them out them once I have some pictures.

One of my assumption is that either the bipolar or more probably the FET is starting to fail, leading to less current flowing to the HDD. This may also be due to R drift, leading the bipolar not able to properly bias the FET.
I'll have to make some additional measurements.

I would not be surprised to find an about-to-definitely-fail component, knowing that it might get pretty hot into this enclosure.

Or, my second guess would be to have HDD requiring more power as they are getting older (in a hot envrionment) ...