My board is dx58so2.
A few days ago, USB devices were repeatedly recognized.
3 beeps after rebooting.
You have reinstalled RAM.
After that, you will not hear any beeps, but the M / B will stop at POST code 58 and the screen will "-" come to a stop.
Postal code 58 is "USB bus resetting".
How do I reset the USB bus?
* I am Korean and I used Google Translator.