I had a couple of clients whos upgraded av famicoms arrived not working right because the kit came loose inside the system during shipping. So here's my quick fix guide-o
If you open your system and you see pins like this:
That is bad....
Here's what it's supposed to look like
There's actually two rows of pins that need to connect but you can't really see the back row it's covered. If the kit is fully inserted properly looking at it from the side it will look like this
the kit should be this high off of the main pcb. If the kit is higher then the whole kit might need to be gently removed and re-inserted. And this kit pcb should be 100% parallel from the av famicom pcb
If you decide to pull the entire kit out so you can properly re-insert it then you must be EXTREMELY gentle, careful, and slow about rocking it back and forth. If you pull it out too hard you'll bend pins from the kit and damage it which will require repair.
I recommend that anybody who receives one of these systems to check that the kit is properly inserted before turning the system on.
You should NEVER under any circumstance try using a toaster NES or NES 2 power adapter on your av famicom. Official NES power bricks output AC power but the AV famicom expects you to feed it DC power. I read that plugging an AC outputting power brick into a famicom can fry the entire system so you should always use an official famicom power brick or compatible power brick on these systems. A sega genesis model 1 power brick will work just fine. Just as long as the power brick outputs DC power around 10 v 850 ma your system should be perfectly safe.