Sony DVD error message

From Toulouse, France, 1 post

I was in the U.S. in May and bought, on ebay, 2 identical Sony DVD players, (DVP-FX810). They have worked perfectly since then but have now both curiously developed the same fault. When I put in the DVD I get the error message "Check Disc", I have cleaned the lens with alcohol, and used brand new discs, with no change.

Any help would be gratefully appreciated.

Timmo191