Loc on radio

Can anyone help? Have tried to unlock radio using 2 & 3 and also 1 & 4 as stated in manual. Does not do anything just says loc. If mn or hr button is pressed it does show Inop. AM/FM button doesn't do anything. I'm obviously not the brightest bulb on the planet but have tried several times & just can't seem to do anything. Lost battery power & car was purchased used. Unemployed & cannot afford to go to dealer, gas is obviously more important than a radio but would greatly appreciate radio working as well as news & road conditions with our bad winter. Not real web savy so if you can possibly help please reply to [email protected]. Not sure what I'm doing wrong. Have a 98 Olds Achieva. Thank You