I have an Amilo Pro laptop with an attached HDD in external USB enclosure. I can't reliably shut down my laptop, and sometimes, I can't start it when the external drive is plugged in. Rarely, my laptop doesn't start at all even after I unplugged the device. I have to power cycle several times before it is willing to start. When the computer is running, everything seems to be fine.
I deducted the problem to the USB connection, as it seems to power-back my computer through the USB's 5V wire, which might lack protective diodes, causing the machine's BIOS to be confused. My questions are:
Is this back-powering property general - e.g. should I buy a new rack to solve the issue?
Does this 5V damage my laptop in any way?
Follow up to my previous question
Update from my comments:
Sorry about the terminology, I have 500GB SATA HDD in a rack, which has its own power supply and a USB cable to plug it into a computer - the OS sees it as jet another HDD. My laptop worked fine before I purchased this external device. It is a Spire GigaPod VIII
It is directly attached to my laptop. It is independent which of my 4 hubs I plug it in. No video at all - I guess the BIOS gets confused about the power status in the system. It seems I have to unplug the cabel, replug the laptops own power cord and then it is willing to start up.
It works without problems. Only at shutdown and startup causes it trouble. If I manage to turn on the laptop, everything works fine, file copy, running programs from it, all. I already filled it with 250GB of stuff and backup.
So, how it seems to work: Before shutdown, I unplug the device without warning - no eject by OS - then perform shutdown. Power on - works - I log in and then I attach the enclosure - HDD works. The strange thing is that it is not enough to unpower the enclosure and leave it plugged in.
If I shutdown 'properly' it powers back. If I eject the drive then unplug it and shutdown, 50% it won't start the next poweron - I have to plug the drive back, powercycle, unplug, powercycle x2 then it starts up. If I just simply unplug, everything shuts down and starts as expected. I checked my windows USB power report, it says two mass storage devices cosume 2mA + 200mA.
I forgot I have a 2nd 15GB IDE HDD (from my old times) in a different enclosure. No shutdown/startup problems with that (I'm relieved)! It seems I have to try a different SATA enclosure for my 500GB HDD.
Changed the enclosure to a different vendor, and it seems the error has disappeared. Thanks.