Avante On/Off issue

[TinCanAlley]

Here's an odd one and I'm not sure where to start.....

Months ago I turned off the SC (which I believe is short for Space Command) thinking it would turn off the heater in the CRT, but found out it didn't. I left it that way and was turning it off and on by pressing the small button under the door. With off, there was no on/off, volume or channel selection. This was fine for awhile, but I decided to turn it back on. Now the remote will change volume and channel, but not on/off the set. So I pushed the button on the panel and it didn't turn off the set. I switched the SC back off, but the button still won't turn the set off. I unplugged the set and upon plugging back in, the set is on. No matter what position the switch is in, I can't turn the set off.

Anyone familiar with this circuit? I'm sure there's nothing fancy about it and maybe the SC switch is going bad and not activating the power button on the front panel?

Anyway, I'm going to dig into the SM, but was hoping the brain power here could shorten my search.

Thanks!