Can't mount old IDE hdd using an USB adapter
Solution 1:
First things first (besides the select jumpers) - are you following the proper power-up sequence?
Connect the IDE-USB adapter to the HDD. Then apply power to the HDD; the HDD must be spinning and ready (heads unlocked) before you plug in the USB cable at the PC.
And be very careful to not jostle the drive while it is powered on!