[Q] notionink adam 2 tablet sound not working topic

i have an notionink adam 2 tablet . i had rooted the tablet using kingo app and installed viper4android effects and chosen it in place of default in music effects . one day the tablet was infected by a virus and became too slow so i did a factory data reset without unrooting or disabling theh viper4android effect. after that the sound and autorotation stopped working . there is no notification or alarm or any media sound from the tablet using headphone , internal a well as external speakers as well as using bluetooth speakers . cm 11 kitkat update was available and was advied so i did the same . everything installed fine , the autorotation started working but sound still not working . please help and provide some insight as how to approach the problem . it was working very fine just before factory reset so i am sure it not a hardware issue . the volume panel appears greyed out similar to when a driver is missing in pc and panels are greyed out . any help will be of immense benefit as rest of the tablet is working wonderful.