OEM Denon RC-939 Remote Control - For AVR-1804 Receiver

The "+" button (yellow circle in pics) is sticking and you have to press alil harder than normal to get it to function but the button does work. The "On/Source" button on top right (yellow circle in pics) is not working. I tried & tried but never could get that button to fire. Great remote other than those to buttons. Battery compartment has zero acid or rust. Not a whole lot of surface scratches on this remote even. All other buttons fired when tested.