Fix 1: If your TV has a shared component video (3 RCA) and composite video (1 RCA) input, you need to make sure the colored plugs on the cable ends match the same color-coded jacks on the TV. Fix 2: For S-Video cables, unplug the S-video cables on both ends and check if there are any bent or missing pins. Fix 3: Make sure you’re not playing an NTSC DVD on a PAL player or vice versa. Fix 4: Convert DVD disc to digital videos like MP4, then you can copy to USB flash drive and watch it on HDTV via USB.

You may check the frame rate and color settings, eg it may play 4K in 30fps or less, you can't play 10-bit color on a 8bit TV... YouTube also plays back 4K using the VP9 codec or HEVC codec, which is really only available in Chrome, and it gobbles battery power and CPU and if it’s too slow, it may be switched to a lower resolution. Youtube may downgrade the 4K videos to 1080P HD for smaller file size, less memory or faster streaming speed, etc.

I think there are a few reasons: 1 Make sure the bought DVD is the same region as the DVD player; 2 the dvd player is too old to support latest DVDs that comes with some newer protections; 3 a defective drive failure problem . Try another disc drive and you may want to take a look at how to make DVD player region-free

Try another disc or try another drive to make sure which causes the problem. In most cases, it’s a scratched DVD or a dirty drive. This post has shown all the possible reasons and fixes.

it sounds something is wrong with the machine. Did you try other discs?