I have a Marquee 8500. After the machine is turned on, the picture begins to slowly change. It seems to progressively turn yellow or green. (I'm partially color blind so it's hard for me to tell.) All three CRTs are on but something is happening to the picture. Does this sound familiar to anyone?

Just to clarify,

The white is turning another color??
How long does this change take??
Is focus effected??



Cheers
Steve

well you need to look into the lenses and see which tube is losing output. If it's turning yellow, then the Blue tube or neck-board is acting up. If you didn't get it with a warranty you will need o take the covers off and start learning how everything works.
It migith be the tube if the machines P14 circuit has never been fixed and filament voltage is too high. If that's the case, you will need a new tube. You need a multi-meter to check it, here's a pic of the procedure at the bottom of this page
http://www.etechvideo.com/techtip1.htm

If your lucky it's just a neck-board. The Video Neck-boards (NVB) are at the back of each tube, you will need to switch the low output tubes VNB with one of the other colors and see if the low emission follows it.

http://www.curtpalme.com/ElectrohomeMarquee_Layout7.shtm