|State the make and model of your brand name system, or if it is a generic system, the make and model of the desktop mboard. |
The specific brand name system model is usually on a label on the outside of the case somewhere, or it can be determined by going to the brand name's web site.
The model of the mboard in a generic system is usually printed in obvious larger characters on the surface of the mboard, often between the card slots.
When did they first stop working?
After you installed a card in a slot on the mboard?
After you installed another USB device?
USB devices may not work correctly when they're connected to certain USB ports, e.g. ports in a hub or on the front of a desktop case. However, they should work in the same port the USB flash drive works in.
Or, if this is a desktop computer, you may have an IRQ problem you need to fix - if you do, you will need to reload the USB stack after you have fixed the problem.
See response 3 in this:
External drives require a lot of power, and they won't work properly in all possible USB ports you can plug them into.
If you plug one into a hub, it could be nothing else plugged into the same hub will work properly when it's plugged in.
See response 1 in this: