Low Video Resolution
I converted my ASRock N68C-GS4 FX system into a testing system. The motherboard remains remains temperamental but nominally useful in the new role.
I connected a hard disk to the system. After booting the video resolution was locked at 1024x768. The monitor’s default display is 1600x900. I tried a Live ISO. Same result.
All had been fine for the previous couple of months using this system.
The system is connected to a KVM switch. I proceeded to swap the output connection cables to see if the KVM was at fault.
The video connector on the ASRock system almost fell into my hand. For some odd reason I never had tightened the holding screws. I tightened the holding screws and booted. All was well again.
Odd the video worked at all but apparently just barely to produce the low video display. Odd the system had been working this way for the past couple of months without exhibiting the problem.
Sometimes the root cause of a problem is simple but computers nowadays are so complex that we tend to overlook the obvious.