My tablet has some issues, so I took it to the doc. to have it X-Rayed. Note the different image contrast across the voltage range.

At 50kV even the circuit board shades the X-Rays also the batteries appear dark. The reinforcement in the plastic housing on the left and right can be seen.

 

At 65kV many details in the circuit board area can be seen. The vibration motor and loudspeaker still appear mostly black. The thin details in the plastic housing have much less contrast.

At 99kV even the loudspeakers and the vibration motor have visible details. The plastic parts of the housing appear mostly white/transparent to X-Rays.

The dark area at the bottom-right on all images is the shadow of a piece of wood that was used to hold the tablet while taking the X-Rays.

Despite having an inside view of my tablet I still don’t know why it’s so damn slow and the battery only lasts one day. :-(