Got one of these (46" '91 model) for peanuts. Had to do a little
tweaking; clean mirrors, lenses, screen and tweak user convergence. The
green gun was intermittent, but following advice here, I found and fixed
a bad joint on the CRT neck board.

The blue crt has the usual contaminated cooling fluid, which I intend to
address next (Green has a few floaters, red seems clear...I'll do them
all, one at a time to chart the improvement.)

My question concerns coolant change advice on the internet; which ranges
from 'suck out the fluid, replace after cleaning through the diaphragm
hole', to: 'completely remove each CRT, disassemble, clean, reassemble
using new O-rings'...from easy DIY job to 'don't even try this yourself'.

Is there a middle ground? It doesn't look real easy to clean all that
gunk out using remote tools; but pulling the guns, even one at a time,
just looks way too involved (sort of like laproscopic surgery). I'm
leaning toward sucking out the fluid, removing the lense assembly and
cleaning with the tube in place; but even 'that' looks to require quite
a bit of cabinet disassembly. The back two screws on the lenses are
under a cover which (I think) I need to remove the back of the set, or
the else mirror, to access.

Any thoughts? The tubes themselves seem to be in good shape. The set
might not have gotten a lot of use...plenty bright.

The only other issue: the brightness control seems to have little or no
effect on the picture. All controls were set at midrange when received,
and tweaking yields little improvement.

Thanks in advance

jak