Welcome to NLG!
Sounds like something came loose during the move.
Start digging around in there with the power OFF.
Make sure every single connector and power supply is connected or seated properly.
I stress the word "every".
Take your time and don't miss anything.
You will find something that just isn't seated right....could even be something like a video card on the MPU.
Even the batteries - there's a few...did they die or lose power while the machine was off?
Check 'em with a multimeter...see how strong/weak they are.
Also, do a search on your platform - not this one...you've posted this topic in "IGT Stand-Alone Progressive Systems? Why?
You have an AVP G23...there's a section just for your machine and PLENTY of topics....
some might be about why you're seeing that "No Sync" error.
Here's a link to AVP G23's...start searching and reading...>>>
http://newlifegames.com/nlg/index.php?board=99.0