USB ports not working

[Snowflake]

Okay, another question from the technically challenged one here.

Among the many USB ports, I have two on my Dell flat panel monitor, which up until a month ago, were working fine. Now, when I plug in a flash drive or the card reader for my digital camera, nothing happens. The PC does not recognize that I've plugged anything in.

So, I paid a visit to control panel/system/hardware/device manager to check on them. Of course, I have what feels like dozens of USBs to check (2 on the front, 2 on the back, a PCI card with 4, a USB hub adaptor with another 4 and the 2 on the monitor) Now, I cannot tell which two are on the ones connected/included on the monitor.

I've gone through each one and done a troubleshoot and according to my PC, they're all working fine.

Anyone have a suggestion? I miss being able to just plug in the flash device, or whatever, in to the monitor instead of crawling all over the floor hunting for an open USB port (yes, I have a whole lot of crap hooked up to this poor tired old Dell)