How can I fix my Accenta 6?

The remote keypad has been going a bit faulty and hard to set.I replaced the keypad,just the same!. Suspecting the battery as it was quite old,I replaced that too.Just the same!I have checked transformer input, I also have 12v to battery terminalsThe keypad remains difficult to set.The red power light is flashing instead of being a solid light.All you clever lads out there, Help