How can I fix a Daewoo ST700D VCR that playbacks snow?

I have a Daewoo ST700D VCR that I haven't used for quite some time. A few days ago I was searching for something, and the first two tapes played just fine, but when feeding the third tape, it looked to be empty. I went back to some other tapes, and they all seem like there's nothing on them now. All tapes still play well on a different VCR.
I'm using the RCA plugs for output and the RF antenna for input. Live TV and menus are still clear and solid.

After a bit of running those types the VCR started "eating" those tapes, so I cleaned the Mode Switch from oil that dropped in, using a napkin and an electronics cleaning spray - this fixed the tape eating issue. I have already had this latter issue once before and fixed it the same way, only this time I was more thorough. I am not sure how it should be with this VCR, but I did notice that when fast forwarding or rewinding (that is without picture) the tape still runs wrapped around the spinning drum/heads.

I later tried recording from TV and then playing on a different VCR – the audio was there but the video was bad – typically, the bottom of the screen would look fine with a lot of noise and horizontal lines at the top (sync???). After a few seconds of playback the LG would pop a blue Dr. screen that suggests cleaning the heads. When replacing the tape or even merely ejecting it, the head status would change back to OK. I verified that the other LG 2 head VCR could record & play on that tape (it wasn't new, but not too old, as I have no new tapes), and it did so perfectly.
I then went back to the ST700D to retest those 2 new recordings and found that for a second I can see some details in both new videos but those would quickly vanish. The audio seemed to hold a bit longer. The ST700D recording was maybe a bit clearer. I went back to the old recordings and they still showed nothing.
How can I fix my VCR?
And thanks in advance!