Thank you for help,,i will try this,,in the past i clean the PCBs ,,wd40 on the little philips because was rust ,and rust kill formula from Nigrin ,,,on another boombox i had nice results with dashboard silicon spray,,, on diferente project i used just liquid soap and water and tooth brush,clean clean ,,,,the list goes on...but alcohol is next ,thank you

Good question.. because i want to save where i can the original parts...in this case gluing back all the blue pieces was a pain in the ass .it took a very long time to finish,the one in the white plate are just what I found fallen inside , there are more of these just hanging ,,