I am not sure where you got your advice but
this Apple Support article is the place to start troubleshooting kernel panics.
From past troubleshooting experience I would start with the least expensive items such as cables, hubs, and devices including keyboards and mice. Just because something has been working for a long time doesn't mean it cannot or has not failed.
NOTE: Your Logitech speaker may be fine, but the connecting cable may be shorting out internally.
