Slow imorovement points to the CRT being a little weak.
The set almost definately has AKB so it adjusts itself. There may be
a way to tweak it in the menus BUT if its OK after warm live with
it.
BTW if you go into the service menus ALWAYS write down the
parameters & save them. Also be sure to exit properly to save the changes.
73 Zeno
LFOD !