Does that include all USB ports, including the front USB ports?
What cards, if any, do you have installed on the PCIe slots, in addition to your graphics card?
When did you first notice that your USB ports seem to stop working?
This would be that time you would try booting to a Firewire external drive, with a native boot system (Leopard to El Capitan) to give you the best chance to boot to "something"
If you can't choose that external boot from the Option key on a USB wired keyboard, or when selecting with a USB mouse, then I suggest that you have a failure on the logic board. (selecting the boot drive on that Option-boot picker screen is provided through firmware, and is not software-dependent
Hello! thanks for answering. Yes, it includes the front ports.
In the PCI ports, in addition to the Gtx 680 card in No. 1, I have the Samsung 970Plus Nvme disk through an Oc Accelsior 1M2 card in PCI No. 2, and on the other PCI, No. 4, I have an Inateck KT card 4004 with 4 USB 3 ports.
The first time I noticed the ports stopped working was one night when I was working, and suddenly my mouse and keyboard stopped responding. I restarted the machine thinking that would solve the problem, but then I never had access to the native USB ports on the Mac.
I estimate that it is probably a firmware problem, because the logic board seems to work correctly and with great performance.
Do you know how to restore the Firmware???
From already thank you for your time. Greetings