"Disk Failed", then "Disk Unplugged" errors

Questions about SNMP, Power, System, Logs, disk, & RAID.
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Shmal
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Re: "Disk Failed", then "Disk Unplugged" errors

Post by Shmal » Sun Feb 16, 2020 3:42 pm

serpentello wrote:
Wed Feb 05, 2020 11:03 pm
My question is.
What functions I will loose bypassing them?
If they are there they must have a function I guess.
I'm only guessing, since we don't have a nice clear circuit diagram to look at, but I suspect it's related to controlling the power either on initial power up of the NAS, or when you hot swap a drive. Something to delay powering on a device or slowly ramp up the power to avoid any sudden power supply draw or feed to the hard drive.

If that's the case, the effect of this fix is to bypass that mechanism resulting in heavier wear and tear on your power supply or hard drive.

You can probably google mosfet switching circuit examples or SATA controller power switching to get some answers.

chripopper
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Re: "Disk Failed", then "Disk Unplugged" errors

Post by chripopper » Sun Feb 16, 2020 8:18 pm

Shmal wrote:
Sun Feb 16, 2020 3:03 pm
chripopper wrote:
Sun Feb 16, 2020 7:38 am
I noticed that there were solder joints just above and below the mosfets, and tracked the circuits on the board and did some measuring. And with my limited knowledge in electronics my conclusion was that connecting these solder joints would bypass the mosfets, feeding the disks constantly with 12 and 5v.

So i just soldered them together and the disks were fully functional again!
Attached is a photo where i did the soldering. IIRC the upper circles is 12v and the lower ones is 5v.
Thanks for sharing the solution for your board, nice job diagnosing it! Based on the picture it looks like the points you found were a resistor in parallel with the mosfet (I think the label is R##?). End result would be the same, bypassing the mosfet.
No problem and thank you! No there were no resistors, just empty solder pads like it was prepared for a resistor. I think the label was B##?? My conclusion was that the left pad was input voltage to the mosfet and the right pad was switched output voltage to the HDD. So it seemed like it was prepared to bypass the mosfets.

I think the only purpose of them is to shut down disks when not in use. Maybe also to start the disks sequentially to avoid high start up currents.
Bypassing the mosfets will of course make them spin constantly.
Again I have very limited knowledge in electronics, I'm only guessing

jezd
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Re: "Disk Failed", then "Disk Unplugged" errors

Post by jezd » Tue Feb 18, 2020 10:29 pm

chripopper wrote:
Sun Feb 16, 2020 8:18 pm
Shmal wrote:
Sun Feb 16, 2020 3:03 pm
chripopper wrote:
Sun Feb 16, 2020 7:38 am
I noticed that there were solder joints just above and below the mosfets, and tracked the circuits on the board and did some measuring. And with my limited knowledge in electronics my conclusion was that connecting these solder joints would bypass the mosfets, feeding the disks constantly with 12 and 5v.

So i just soldered them together and the disks were fully functional again!
Attached is a photo where i did the soldering. IIRC the upper circles is 12v and the lower ones is 5v.
Thanks for sharing the solution for your board, nice job diagnosing it! Based on the picture it looks like the points you found were a resistor in parallel with the mosfet (I think the label is R##?). End result would be the same, bypassing the mosfet.
No problem and thank you! No there were no resistors, just empty solder pads like it was prepared for a resistor. I think the label was B##?? My conclusion was that the left pad was input voltage to the mosfet and the right pad was switched output voltage to the HDD. So it seemed like it was prepared to bypass the mosfets.

I think the only purpose of them is to shut down disks when not in use. Maybe also to start the disks sequentially to avoid high start up currents.
Bypassing the mosfets will of course make them spin constantly.
Again I have very limited knowledge in electronics, I'm only guessing
Massive thanks to both of you on this, I own a TS-451A too and both bays 3 & 4 power dropping has cost me a lot of money simply because its normally safe to assume its drives that are failing, so you purchase new drives (upgraded too) and then you find the same errors occurring. In my case bay 3 can spin up times but soon after (mins/hours) will start to click and lose power eventually, bay 4 will do similar things but far more intermittent over many hours.

It's been a expensive nightmare but knowing that I am not alone has been music to my ears, more important is the great work you have done - I will take a look at my backplane next and report back.

I'd consider changing the mosfets but if there is an inherent issue with then overheating etc then maybe the bypass solder jumper is better.
TS-451A with drive stuff installed

WillHuu
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Re: "Disk Failed", then "Disk Unplugged" errors

Post by WillHuu » Tue Mar 24, 2020 5:10 am

I'm using a TS-831X with 8x8Tb in RAID6 and had 2 bays failing. The disks tried to spinup and failed, over and over again producing the 'clicking' as described in this thread. Sometimes, the NAS did boot correct and started rebuilding, but always failed eventually.
After testing both disks multiple times on different systems without any issues, i desperately bought new 8tb hdd's to be able to have the NAS working again. But my worst fear came true, the same unreliable behavior occurred again. Looking for similar experiences this thread showed up. And i'm glad it did!

Reading about the dysfunctional backplanes, and QNAP not replacing them within acceptable price-range made me quite disappointed.

As at least one user mentioned, simply cooling the unit made the issues disappear. So, i first tried just manually setting the fan to max speed. It's a bit noisy but, huh, the NAS seems stable?! Rebuilding finished successfully and in an attempt to tune down the noise i turned on the 'Smart Fan' automatic fan adjust again. Set manually to the minimum possible thresholds, low speed at 35°C and high speed at 45°C. Within half an hour, both disks failed again!

Now, i simply placed heat-sinks on all MOSFET's, and the system is running fine for days now, with the automatic fan speed turned on.
Rebuilding without issues, and both the old HDD's and new (but ofcourse..) HDD's passing all tests without issues.
Assuming the MOSFET's will fail eventually, it feels great to know i can still bypass them completely when needed.

I really wanted to share this experience since it has been quite a hit on our workflow and my wallet.

I can't thank the community enough, especially the users who tracked down the actual issue with the failing MOSFET's which are responsible for the HDD's power management.

And for any QNAP employees / developers reading this, it would be nice to be able to adjust the automatic fan thresholds to lower values.
A minimum of 35°C for low fan speed and 45°C for high doesn't make sense, at least the ability to set it lower would be nice. And could probably expand the lifetime for a lot of your sold products.

dolbyman
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Location: Vancouver BC , Canada

Re: "Disk Failed", then "Disk Unplugged" errors

Post by dolbyman » Tue Mar 24, 2020 5:36 am

QNAP does not come here .. but thanks for the writeup

agmjr
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Re: "Disk Failed", then "Disk Unplugged" errors

Post by agmjr » Fri Mar 27, 2020 7:02 am

chripopper wrote:
Sun Feb 16, 2020 7:38 am
I noticed that there were solder joints just above and below the mosfets, and tracked the circuits on the board and did some measuring. And with my limited knowledge in electronics my conclusion was that connecting these solder joints would bypass the mosfets, feeding the disks constantly with 12 and 5v.

So i just soldered them together and the disks were fully functional again!
Attached is a photo where i did the soldering. IIRC the upper circles is 12v and the lower ones is 5v.

I just wanted to throw it out here, if it can help somebody else please let me know!
Of course this is at your own risk and only as a last resort. Always consider RMA in first hand.


By the way this is my last qnap device ever. I really liked it until this happened and i noticed how common this problem was over various model ranges. I think the sata controller board would be the the part thats least prone to failiure.
hi...i have a similar nas and similar issue...do you a picture of the "finished" product of the solder joints that you made? i am not so confident on electronics but a picture could help explain what needs to be done to a hired technician :D . thanks much

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