USB hard drive no longer mounting

[cliverlong]

(17th Jul, 2014 02:22 AM)IriDium Wrote:  This certainly looks like a power problem to me, but I have no idea why it used to work but not now.

A 4 port USB hub should have at least a 2Amp rating 500ma * 4. So your 1.6Amp PSU means that each port is only getting 400ma.

If the caddy is trying to draw 500ma it could only be getting 400ma.

A "normal laptop 2.5" HDD is about 2 watts, so ~400ma. A 3.5" HDD can be 7 watts, so about 1amp.

USB flash drives only consume ~100ma which could be why they are being mounted.

Do you hear the HDD spinup when connected?

Do you have the equipment and skill to test the power requirements? E.g amperage when the HDD is connected?

Try booting the RPi without the ethernet dongle connected - if that works it is power, as a Wifi dongle can draw 400ma if it has a low signal. Also try powering the caddy with another USB PSU - like a phone charger > 1amp. Try swapping USB cables around, some are better than others.

If you have a spare SD card, try installing Xbian and see if that works. If it does, then "something" has changed which is causing your issue.

I'm afraid, it's now a process of elimination as it certainly doesn't (Famous last words) seem like a S/W issue.

If still no luck, post the make and model of the caddy and HDD. Might show something up.

Also post just output of "dmesg", "df -h" and "mount". xbmc.log is no use at this stage.

This all seems plausible to me

Would the following hubs have enough oomph?

https://www.modmypi.com/New-Link-4-Port-USB-Hub-(USB-2.0-with-Mains-Adaptor)

http://www.amazon.co.uk/gp/product/B00DR8QSQ2/ref=noref?ie=UTF8&psc=1&s=computers

I have a digital multimeter but don't know how to use it to check the current drawn by the caddy. Are there instructions online on youtube?

Thanks

Clive