BSR4EG Electronic issue? Need Help!!

[jeremy jones]

I'm having some strange things happen with my BSR4EG.. It started cutting out like the battery was dying. It sounded like alot of static and the bass volume would go up and down.

I took off the back panel and replaced the battery.
Now when I plug my bass in no sound comes out at all.. unless I pull up the volume knob then it sounds perfect.

I took the battery back out and there was some crud on the contact so I cleaned it off. It worked until I unplugged it from the amp and replugged it in. Now the same thing is happening! It seems like the contact on the battery might not be working right. Its def not my amp or any cords.. I tried several different ones with the same results..

Any suggestions?