In this video, I discuss how to unlock the factory stereo. If the battery is unplugged (or power is otherwise disrupted from the stereo), the stereo will require a code before you can use it again. If you input the wrong code 3 times in a row, you will be locked out and the display will say "OFF" whenever you try to power up the stereo. If this happens, you will need to keep the stereo powered up (displaying "OFF") with the ignition switch in position II (sometimes position I will work) for 3 hours. I like to keep a battery charger hooked up to prevent the battery from draining down, since the vehicle's electronics will be powered up for several hours. After the timeout period has passed (typically 2.5 to 3 hours), the stereo display will switch to "CODE" and you will then be able to input the code. If you do not have the code, you will need to contact a Volvo dealer to get this code. My local dealer was happy to supply me with the code for free, and I was on the phone for only a few minutes.
