My computer keeps entering 'Digital Power Saving Mode'. I have an LG Monitor, HPE-150F tower with 700W Thermaltake power supply, which I bought today to see if my power supply is what's causing the problem. I am running EVGA Nvidia GEForce GTX 640, I also have Asus 1050ti Dual (on the side to test out to see if the issue is with psu or gpu , this card is also new). This problem only occurs when I put in a different graphics card other than the one that came with the PC. I have used EVGA card for a while and it never had a problem, until recently. Any help will be greatly appreciated.