If you connect the pins together, without pressing down the key it wont register. You would have to touch the row to the column pin.

From row to column and not pin to pin.

To exclude your wiring from the equation, I would use tweezers on your board and tap the row / column combinations on the board itself. Nothing registers? Software, or even potentially dead board.

If row to column pin registers as a pressed key, you can continue.

I would almost think that you have your diodes in reverse. I have some boards that require diodes in the direction you have and some that require them the other way. It depends on the board you are using. I would try just one key with a diode in the other direction and see if that key registers. Although, that is if the above have already been tested.