1975 Zenith Solid State console no color demod

[Mangie]

Hello yall! I got a 1975 Zenith all solid state console set. Model G4547M, Chassis 23GC45. I got the service manual on order. I have basic knowledge and troubleshooting skills on a few vacuum tube sets I own and worked on. This is my first Soild State set. I probably qualify as a noob. Lol Thought I'd see if any pros out there can point me in a direction to start looking. Also if there is any good service tips or things I should do to this set before it goes into semi daily use.

Here is what I've checked out and noticed so far.
First it has a nice good solid black and white picture.
CRT tests really strong and equal on all 3 color guns.
If flip the setup switch on the Croma board, I get a barber poll like colors. Same if I adjust color killer pot. I cleaned up all pot controls.

Looks mostly un touched behind the back cover from what I can tell. However the tuner shield is missing and the ground strap was removed and not reconnected. Not sure if that was from as half attempt at a previous repair or if this was where the previous person tracked the color problem down too and quit at this point.

Thanks much everyone!