on my 92
once and a while it too would not come on, so i would twist it and it would work. i did retire it soon after.
and i had a pro 34 that got "radio CPR" on it so the sound would work, that meant the radio was laid down and a gentle tap on the front. i now have a uniden 396 that i have to push something in the headphone jack to get the sound back. good luck.