I purchased PN EPM7192SSQC160-10N dc 1149. They had form and shear marks and clean leads. The top surface was found to have been blacktopped after I tested it with heated solvents. Is it possible that it may have been done at the Factory (Philippines)

The above devices appeared to be in original condition all showing form and shear marks on the leads but when I tested the top surface with some heated solvents the surface came off and there was no other markings below as the markings only went thru the top surface. Is this possible? Could this have been done after the devices were tested?

thanks,

Don leRoy

Quality Engineer