USB ports suddenly stopped working

My main desktop which has been going through a bit of a patch at the moment now has all USB ports acting very strangely in that plug something in and the insert sound goes off but nothing shows up in Computer and even Kaspersky does not ask if I want to scan it.

The machine has the usual back and front ports and also a card reader (Icy Box with 2x3.0 and 4x2.0 and SD etc slots)

Now I have tried chkdsk /f /r sfc MBAM SAS ADW full Kaspersky scan and tried the sticks and drive sin my other machines and all are good. Have installed all the drivers etc etc but still no go.

Any ideas please before I run a rescue disk and memtest as I seem to be running out of options. Boards about three years old now - Asus P8Z77-V

It could be the Southbridge chip on your motherboard going bad, John. Do the temp and fan sensors all still work right?

Ok mate I take it you mean the 24 pin power plug to the board I will do that although I always shut down all machines when done for the day except when running memtest of course.

Plus I think maybe Mellon might be right too as I have other problems for sometime starting with losing posts back to threads in this forum which we couldn't pin down t anything in particular even a clean install (twice) has not fixed it.

I did notice the Device Manager this morning showing the yellow triangles on the USB controller but got them back with the Asus CD install stuff that came with the board but still no sticks or external drives recognised,

I even tried disabling Kaspersky because it offers a scan on plug in USB drives but again no go. So being out of warranty looks like a new board eh? If I do am wondering what brand to go with as I thought Asus was meant to be one of the best. Trouble is it also mean a Haswell CPU too because the current board is a 1155 socket.

Ok Gokhan mate it has crossed my mind to default the BIOS as it is OC'd right now - just the CPU a bit - 4.2Ghz and the RAM to max out at 2400MHz and to be honest I really don't think even with that the machine runs any after at all because I ran it at stock speeds when I first built it.

But as soon as I get chance I will do that other stuff you linked because besides the cost of renewing the board and CPU the thought of undoing it all and dropping another in is really something that I don't want to do out of choice. .