Likely cause of games not progressing beyond title screen?

I recently got a PAL SNES from a car boot sale and can’t seem to get it to work. The console powers up but will not go beyond the title screen for any of the games I have tried. I’ve taken it apart and can’t see any obvious damage anywhere. I cleaned the cartridge slot with isopropyl alcohol, hoping for some tips on what to check next before biting the bullet and getting another console.