I would not go beyond the " clean & balance" setting if you
rejuve. Sony jugs just dont take it. Most the time in a few
days they look like dog doot again. You can also H-K short it.
As far as grey scale goes make note of where the pots are set
then tweak things, there is no service switch. Do it in
a low light room & dont expect to drive the set balls out.
She's old & tired, & wants respect....
73 Zeno