Sony HDCAM HDW-700A Operation Manual page 58

3
Check that there is no slack in the tape. Then slide in the cassette
until it clicks into position and close the cassette lid completely by
pressing near the engraved "PUSH".
3
Note
To insert the tape correctly, make sure the tape in the cassette is facing
up towards you before you try to close the cassette lid.
Checking the tape for slack
Pressing in the reels lightly, turn them gently with your finger in the
directions shown below. If the reels will not move, there is no slack.
3-2 Chapter 3 Recording and Playback
Checking the tape for slack