Sony DCR-TRV140E Digital 8 tape problem
Ok, so it turns out that after a large amount of research into error codes, the Error: e:31:23 means that there is a problem with the right hand side tape reel cog. It appears that the cog cannot move the spool, as it clicks a bit before displaying the error when I insert a tape. I think this can only be fixed by a specialist, but I included this answer to give someone in the same situation a resolution.