Geeetech

I have a 2up3d printer. It was shipped with the Geetech PrintrBoard Ref D.
I'm using repetir Host, version 1.0.6 to Generate g-code.

My Z axis steeper motor, stopped working in the negative direction.
To test movement, i moved the Z-axis wire's, female connector, to the controller's, Y-axis male connector.
The Y axis female connector was relocated to the z-axis male connector on the board.
The z-axis worked, and I lost Y movement.

I ordered a PRINTR Board REF D. from amazon
I installed the new board and connected all wires, exactly the same, correct way, as the first board.

Repetir Host cannot not establish a connection, with my second board. I am receiving the following error message from RepetrHost

************** Exception Text **************
System.ArgumentException: The given port name does not start with COM/com or does not resolve to a valid serial port.
Parameter name: portName.

Next I re-installed the original (first) board. Repetir Host is able to connect to this board.
but his board has a lost axis.

Is firmware installation needed on the first board?
If yes, where can I download the firmeware, and installation instructions.

If firmware is not needed, what should I do, to get my printer operating properly.

Thank you, for all of you assistance.

"My Z axis steeper motor, stopped working in the negative direction.
To test movement, i moved the Z-axis wire's, female connector, to the controller's, Y-axis male connector.
The Y axis female connector was relocated to the z-axis male connector on the board.
The z-axis worked, and I lost Y movement.
"
You don't have to buy another board, I think the Z axis driver is dead, try to swap it with X or Y 's, see if it works.

I'm looking at my board.
I'm assuming the axis drivers are the black chips that are near the axis connectors?
Are the drivers soldered to the board or press fit?

Oh I see your driver is soldered on the board...then how about the wire of the Z axis? is it OK?