Intel Pentium G3420

Hi, so I tried to delid my cpu yesterday but it's really hard. So I decided to undo my intention to delid the cpu. After I installed the cpu, ram etc, my buzzer emitted a long beep. After I checked, remove the ram one by one, apparently the first ram slot could not detect the installed ram...

So ordered another ASUS VE247H 24 inch Monitor for dual monitor setup, around a month ago. Ever since setting it up both monitors, my old monitor (call it monitor A) has been flashing on and off every 5 - 10 mins, like its changing resolution (but not changing value) and going black then coming...