Sony, Sharp VCRs eject issues, can't play?
 

Hello, I have two different VCRs with the same problem.
1) The Sharp VCR takes the cassette and when I press play it spins the drum over the tape for 3 seconds and then stops and goes into standby mode. all rubber bands are intact. visually nothing is broken. cassette rewind works in both directions. cassette ejection and cassette ejection works fine.
2) Sony VCR. correctly accepts and ejects the cassette. rubber bands are ok. When I press play the same thing happens. but rewind does not work, although the motor is working and returns the film to its original position when removed.
attach video link:
https://youtube.com/watch?v=jvHVc1QEDg8&feature=shares
How can I repair them?

It depends on what's wrong with them, there are literally 100's of root causes of such symptoms and only a qualified technician can diagnose them, But I would start with the mode switch assuming you have the skills to take things apart.

The video moves about too much to clearly see what the supply and take-up reels, tape, cylinder etc. are doing through the entire cycle. The shot shoudl be steady and show all the above full time so we can see the movement of the tape and reels and pinch roller/.

An noted above many issues could cause this. Two quick questions:

Does this happen with all tapes or just some tapes?

Does the pressure roller make good contact with the capstan and tape so it can pull the tape through the system?

Before you dig too deeply you should have the appropriate FSMs in hand and the necessary technical skills to delve into the unit.