Vtech 1930C keyboard overlay?

My keyboard overlay on the Vtech 1930C phone has gone bad and want to know where I can find a replacement overlay as when push the phone button, get no dialtone or noise of turning on and also when I press the number 1 button, it won't register in LED screen or make the beep sound. This is the only thing wrong with the phone, all other numbers and buttons work perfectly. Please help as these have battery backups and don't want to get rid of the phones, I have three of them in concrete building, no interference, even on the same channel.