USB drive not ready

[Hugo Wau <wauhugo@yahoo.com>]

My external 500 GB USB drive had never worked immediately, but when it 
was warmed up, it finally connected and could be used. But now have I 
come to a point, that the connection does not work any more - not with 
ohci_hcd, nor with ehci_hcd, when the letter "o" (in *o*hci_hcd) gets 
replace by an "e" in error messages like this:

usb-storage: device found at 6
usb-storage: waiting for device to settle before scanning
usb 1-1: New USB device found, idVendor=04b4, idProduct=6830
usb 1-1: New USB device strings: Mfr=56, Product=78, SerialNumber=100
usb 1-1: Product: USB2.0 Storage Device
usb 1-1: Manufacturer: Cypress Semiconductor
usb 1-1: SerialNumber: ############
usb-storage: device scan complete
usb 1-1: reset full speed USB device using ohci_hcd and address 6
usb 1-1: reset full speed USB device using ohci_hcd and address 6
usb 1-1: reset full speed USB device using ohci_hcd and address 6
usb 1-1: reset full speed USB device using ohci_hcd and address 6
scsi 10:0:0:0: Device offlined - not ready after error recovery

Google showed me, that there are many with similar problems. I tried 
several proposals - but found no working solution so far.

After many trials and tests do I need to get my system in order again - 
of which the backups are on the actually not accessible external hard 
drive. (An USB-memory-stick always kept working without any issues on 
the same system.)

   1. Which kernel modules are needed (and which are to be avoided) for
      to connect an external USB hard drive to the system successfully?
   2. Which software packages and library packages are needed (and which
      are to be avoided) to operate an external USB hard drive successfully?
   3. What should the /etc/fstab look like for which kernel version?

Thanks in advance.

Hugo Wau