mertian

Trying to keep these alive too see if anyone can help me...

Hello I'm probably asking something someone else must have ask before but I can't seen to find an anwser I got a Lexus ES250 1990 and after some repairs where made to it the radio stop working. The radio Security has been Activated and I can't seem to Access it. I know I should hold the start button + 1 and 6 until it blinks but or it never does or I have to do something else I'm not doing. I know the security code but I can't enter the system to put it in. Could someone give me a complete procedure of what to do...