I'm a pro, and don't just mean I get paid. That back panel on the
CTC169 is to be removed for service. Others don't do this. There is a
metal frame on the board and between that and other things you can keep
the pressure even when you pull. This is impossible when the plastic is
in place.

Anything stickying up the wicket makes it all worse. Once I get my
hands in the right place and pull, if it doesn't come I cut the rails.

RCA is great with this mounting, you spill one drop of Coke into it and
it's wrecked. I worked on a CTC140 one time that had the foils peeled
off in those tracks.

I always take the plastic shield off a CTC or PTK169 before anything.
Now realize that I can troubleshoot any of these chassis' with a dead
set symptom in about 2 minutes after that, if even that long. I have
literally worked on hundreds of them. I am telling you, remove the
plastic backshield from the chassis. Failure to do so can result in
overstressing the SMD components at the very least. Then you get
intermittents that can be very hard to solve.

On your last point, none of us use, well to my knowledge, service
switches, even if they exist. You use the G2 and bias to get color
balance with the contrast all the way down and the brightness at
factory default. The color is all the way down, you get a balance down
there, and make SURE you don't have retrace lines, then you crank the
contrast and the drives (on that chassis it is red/blue differential
and green), are what balances the high brightness areas. Some find it a
bit difficult to work with this setup, but not all.

There is a master setup procedure for all sets. I'll tell you but not
now. I must go.

The old bed/worktomorrow cross.

JURB