What you are looking at is the back of a very large vacuum tube. The bits you're looking at are the low voltage connections. You'll probably only find voltages of a couple of hundred volts here.
The back end of a colour picture tube has three electron guns, connections for various elements which focus the beams and coils which generate magnetic fields to deflect those beams.
On the side of the tube closer to the front week be a connector for several tens of kV.
Many of these connections can have voltages which can give you a really bad day. These voltages in some cases can persist for a long time after power is removed.
Why do you think you have a problem with the picture tube and why do you want to try to fix it?