Bullseye rainbow of colors

In some cases this is due to the fact the internal degausser stayed on too long and magnetized the CRT causing the rainbow effect. The only way you will know if the set can be repaired without replacing the picture tube itself is to have a technician use an external degausser to see if they can remove the magnetism on the tube and return the set back to normal. If that works then the internal degassing circuit will have to be repaired otherwise it will happen again when you turn it on the next time. If it doesn't work then the tube was damaged by the internal degausser and at that point you will spend over 300 dollars just in parts to repair it.

This is either a purity fault which is caused by magnetism affecting the screen. You would need to call a service engineer to remedy this as a special tool is required called a de-gauss coil. However there is also the posssibility that it could also be a fault with the shadowmask which is caused by the CRT itself, if this is the case then the CRT will need replaced & this would probably not be economical.