When you replaced the CMOS battery did you purchase a new one or use one you had sitting in a drawer?

Thanks for quick responce! Before I post my problem I have already seen older posts for similar issues! I use two new batteries for that! 

By any chance is there purpose for unplugging PC and then plugging back in 1 hr. later, is it due to PC malfunction?

Even if one was just doing that just to do it, PC shouldn't give you trouble.

In the scenario in which PSU button is pushed and power light is amber, does it stay on that way?  Solid amber is possible bad MB, or going bad.  It does sound like something is faulty if removing and reinserting battery is the only way it starts.  Is the PC plugged in or unplugged when removing and reinserting battery?

Could be a CMOS issue which isn't exactly fixable.  The issue(s) point to that or a different MB problem.  If you want to keep the 390 going, MB's are fairly cheap to reasonable on eBay.

With the PC off, when you push the PSU test button, does it give you the green light on the PSU?

One more question - Does your 390 have the latest BIOS that's for it?  Kind of out of curiosity.  If not, I don't know if it's dependable enough to update BIOS.  Any hiccup updating BIOS can brick an MB.

There is no reason, the power can simply be cut off at some point. When I start from the power supply button it works but it does not open and the button is orange. For it to work it must be unplugged when I remove the battery.