[Chris Wright]

when you playback the original or the new rendered file does it get blurry? what are your render settings?

for the smooth playback, it may be too uncompressed and thus too much MB/sec on your hard drive disk speed. if you try prores or dnxhd, you’ll find it plays back smoother. or you could buy an SSD hard drive.

[Chris Wright]

Use Time interpolation optical flow to go from 30 to 24fps. Size too big? Inside premiere for smooth playback or in vlc player?

[Chris Wright]

Check the crash log. If you can’t render out a prores, dnxhd, or cineform without crashing, render out a png sequence and see where the frame count stops to find the bug. then render around it and merge the audio.

[Chris Wright]

https://forums.creativecow.net/docs/forums/post.php?forumid=3&postid=987742&univpostid=987742&pview=t

[Chris Wright]

try half resolution playback.

what does your cpu usage look like? what does mediainfo say about your video codec? is it h.264?
do a benchmark on your hard drives to see if they can playback mb/sec of your video with crystal disk mark.

if you want to try offline editing and replace clips prores proxy as an alternative because its easier on your cpu for decompression.
https://helpx.adobe.com/premiere-pro/using/create-clips-offline-editing.html

[Chris Wright]

its Shift+PRNTSCRN or FNT+PRNTSRCN maybe. then CTRL+V(edit paste) in mspaint to see screenshot.

[Chris Wright]

Is the hd motor spinning? Are both sata and power plugged in?
Is sata enabled in bios?
Is the usb header port plugged into the motherboard?

[Chris Wright]

you need to start from scratch.

for example, did you ever change the old graphics drivers?
is nvidia control panel set to use premiere.exe ‘always’ while loaded?

have you done a stress test on your components with passmark95 to detect overheating and damaged parts?

at this point, I’d wipe the OS, reinstall only necessary drivers and check temperatures as overheating can cause software failure.

[Chris Wright]

usually its because a codec is used that doesn’t support as many audio channels. cineform, for instance, can handle a lot of channels.
some codecs only support 2 channels.

[Chris Wright]

If your monitor is not color calibrated to srgb, nothing will look right as premiere
is hard coded to srgb and will ignore any color profile on your monitor.

You can use transform luts from p3 or adobe rgb to srgb with lumetri. Also,
Set vlc to opengl video to match opengl driver gamma in premiere. Quicktime
Uses direct drivers with 16-235 pixels which changes the gamma.