So basically, I removed my 750ti as I'm selling it to upgrade in the future. In the mean time, I want to be able to run my PC on the integrated graphics inside my i7 3770k. Whenever I turn the PC on, there is no display on the monitor. I've tried removing the battery from my mother board(ASRock Z75 Pro3) and the problem persists. I've tried both with an HDMI and also a VGA cable. Any help is appreciated.
Go to BIOS (UEFI)/Northbridge Configuration/Primary Graphics Adapter and be sure everything is correct there. It should find the iGPU anyway, but set it as first for now.
Have you ever used the iGPU on the i7 before?
I can't think of any reason the iGPU isn't producing a display, then. A dead iGPU is possible, but seldom happens. Especially if it has never been used. (Unless heat from heavy CPU OC'ing damaged it.) I'm assuming the video cable and monitor is OK, of course.
The motherboard could be the issue, tho.
You might want to try breadboarding the motherboard outside the case; connecting just the CPU/cooler, PSU, RAM, monitor. Start the system by momentarily shorting the two pins that the case's power button would connect to. See if it produces a display.
That will at least let you know the problem lies with the processor or the motherboard.
I wouldn't think the CMOS battery or bad contacts on the RAM would affect jusy the video output. I'm still leaning towards the iGPU/motherboard or monitor or cable. But I'm glad to hear it is working again. Try wiggling the video cable at both ends and see if the display is affected.