Can't get the back on

Send it to Service.

Can't be much help on this one, but if the watch is malfunctioning after you took it for a battery change, then why not take it back and demand that they put it right?

Take the battery to an auto parts store and have it tested, that would be the first step, just because you charged it doesn't mean it is charged.

+ side up(faces the removal back cover)

mcdevito75 here, You may have the mechanism off center with the buttons, remove the back, note where buttons touch the mechanism and line every thing up, you could have moved the mechanism away from these buttons while changeing the battery.

There is a press to put this back on.

RECOMENDATION:
Seek professional help.

GOTO
http://www.watch-clock-makers.org/
Hope this tip helps.

r/ David
http://antiqueclock.clockstop.com/

Took out the battery for 3 min and put that back

If it's a quartz (battery powered) watch test the voltage of the battery. If below 1.5v then replace with new. Ensure battery contacts make good contact with the battery and are free of corrosion/rust/contamination of any sort. Check operating manual for any specifics regarding battery replacement proceedure.

I had the same problem and attempted what banjodoug suggested above. It did not help. I had a faint display even before I re-inserted it into my watch frame. I surmised it wasn't the battery position.

I then took apart the damn thing and put it back together several times, each time rushing to push the setting/center button only to derive the same problem over and over.

I then took it apart one more time and pinched in all of the sides of the metal frame that holds it all together, thinking that I had a bad ground. After I did that, I reassembed it and waited. The display came on with the test display and then eventually went to the standard display on its own and all was good to go.

I suspect the issue was solved by correcting an improper ground and a proper initialization process - both solved by the steps I took above.

Hope it works for you!

I suggest you have to check your battery first. It may be underpowered. Replace it with the new one and then check light again.