Sleep mode/turn off external hard disk?

What is the make and model of your USB drive?? Do you have a powered hub available you can put between the TC and the USB drive.. even an unpowered hub would be interesting to test.

Can I make it work so that only when I access it on my MacBook it turns on?

Basically no.

Your Mac cannot control network disks.

It will send a spin down command to the disk if it is plugged into your computer. And I recommend you do test it.. does the disk spin down when plugged in locally.. if not the problem is the external drive is simply not responding. Or if it works fine on the local computer but fails connected to the TC, it is because the TC is NOT a NAS.. it is not actually designed to control things like USB drives.. Most USB drives will spin down themselves after a period of no use.

Let me also add the opposite problem.. many people find that after a day.. the computer cannot get the USB drive connected to a TC or AE to spin up. Or even be recognised. I am having exactly this problem right now.. as I started testing for another person having problems.

Yesterday my USB drive was recognised but refused to spin up.

Today my USB drive has completely disappeared.

So your continually spinning always active USB drive may be advantageous.. because if you cure the problem and make it go to sleep.. unless you are a prince.. you might not be able to make it wake up again.

Add me to this list, i came here searching if it was only my setup having this problem but I see that I am not alone

"Let me also add the opposite problem.. many people find that after a day.. the computer cannot get the USB drive connected to a TC or AE to spin up. Or even be recognised. I am having exactly this problem right now.. as I started testing for another person having problems.

Yesterday my USB drive was recognised but refused to spin up.

Today my USB drive has completely disappeared."

I put a powered hub between the TC and the USB drive.. It has improved the situation.. but let's say I don't think cured it.

At the moment I am trying to read a file on the USB drive.. which is churning away now for several minutes. Finder is locked up.. and spinning wheels of death are upon us.

Me three. Power cycle the Airport Extreme, drive comes back to life and I can run a TM backup. After 1-3 days, drive is inaccessible from MBA and iPhone, and need to powercycle Airport Extreme again.

Apple Store guy said he's never heard of this issue.

My setup:

Airport Extreme 6th gen

USB Printer

USB HD

USB powered hub

Macbook Air mid-2013, running fully updated El Capitan

What I've tried:

- replaced the airport extreme 6th gen

- replaced usb powered hub

- replaced usb hard drive (initially had desktop powered one, then tried mobile drive with usb power, then back to desktop powered)

What I'd like to try:

- rollback firmware on the Airport Extreme 6th gen (but I have no option to rollback to any older firmwares when looking via Airport Utility on my iPhone and my MBA)

Since I've seen reports of similar instances when running Yosemite and El Capitan, I think it's an issue with the actual Airport Extreme 6th Gen.

Everything you wrote is everything I have experienced and tried tried except replacing the AE but including doing a manual reset on the AE, I would also like to try rolling back the firmware, hopefully someone knows how to do it because this set up is really getting annoying have to power cycle the AE every couple of days, have been thinking of powering it from a switched receptacle to keep from having to reach behind and unplug every time

YatBob wrote:

I would also like to try rolling back the firmware,

You cannot roll back firmware from 7.7.3 on the latest TC. It was a security upgrade that once loaded blocked any downgrade.

If you have earlier AE, then it is relatively simple.

Hold down option key and click the version number of the existing firmware in the summary page.

A list of available firmware will appear. Not all options will work on every model.. but I generally find 7.6.1 the best.. although 7.5.2 was very good on older units.. I think it is very hard to roll back that far .. you could try it in two steps.. roll back to what you can and then see if a further roll back is possible.

eg The first of the Gen5 AE (Gen4 TC) were released with 7.5.2 and could be rolled back but the later production came with 7.6.0 and did not allow it.

Big Ugly BUTT..

I don't think firmware is going to solve this. I will have a go with another unit and see.. but it is very inconsistent..

In testing over the last few days.. the USB drive refused to spin down.. Although I think I left it mounted in finder which could be the problem.

The fact is.. if you want a hard disk on the network.. use the internal disk of the TC or buy a proper NAS that internally controls disk spinup.