RCA VR634hf 4-Head Hi-Fi VCR (keeps shutting off and ejecting tape)

Hello,

I have an RCA VR634hf 4-Head Hi-Fi VCR, only a few years old, and it's
been behaving odd for quite a few weeks now.

When I put a cassette in to play, it'll play for about 7-10 seconds,
then it shuts off with the 'tape not inserted' symbol blinking. When
you turn it back on it simply ejects the tape. This also happens with
timer recording.

I'm hoping it's something I can fix with a little bit of instruction.
Any insights would be much appreciated.

Thanks very much.