Portable DVD players (OX4 Temple Cowley)

I have two portable dvd players.
One works intermittently. (I think the spring that opens the door has lost some oomph. Since I've bent it more the dvd player works better, but maybe someone can improve its reliability). This one has a power cord. I don't know how good the battery is for use without the power cord.

The second one has no power cord, but can run from the same power cord as the first one. The player switches on ok, but doesn't seem to recognise when a disc is in it. Again, it might be the spring on the door, but I can't seem to get this one to play discs.

(The sticky instruction labels on the first dvd player are easily removed)