A cable tester saved me from a 3 hour drive to Best Buy
My nephew was over last weekend and his new 4K monitor kept flickering. I was about to buy a $70 replacement HDMI, but he grabbed my old Klein tester from the truck and found pin 19 was dead inside the wall plate. Has anyone else found that the weakest link is usually a wall jack, not the cord itself?
Did you check the wall plate for corrosion or a bent pin first? That exact thing happened to me last year, turns out the keystone jack had a loose terminal on the back, not even the cable. I spent an hour reseating everything before I finally found that little screw connection had worked itself free.