no display on my after market cd player after battery disconnected ?

Hi can anyone help me i have a vauxhall meriva 2004 which origibally came with a double din cd player which I changed for a kenwood single din which worked perfect for a couple of months but after needing to do work on the car and recharging battery the cd player does not work it has power as it takes cd in and ejects it but the cd player wont turn on ive tryed every fuse linked with radio/infotainment system please can some one help