GameStop Wireless Original Xbox Controller - Power Issues

I have a Wireless GameStop Original Xbox Controller that will power on for a second and then power off. The battery cover was corroded, but I got just about all of the corrosion off. I've tried brand new batteries and it still has the same problem. How do I fix it?

 

Remove all the corrosion with some very fine sand paper to make the contacts shiny. Since this is aftermarket junk I personally wouldn't bother with the time.

 

I managed to reflow the solder joints inside the controller. It now stays powered on. The current problem is that I cannot get the controller to connect to the receiver. I've already tried reflowing the solder joints inside the receiver and the solder joints on the module inside the controller. How can I get them to connect?