Trying to fix Mame Cabinet

[Termophilus]

Hi,
I'm trying to figure out how to fix a Mame cabinet of a friend of mine.
Its a PC with an usb receiver and two joystick cabled in an old arcade
cabinet, working on Windows 7 and Mame. Some time ago a failure in the
power supply fried all the old motherboard usb ports, so we change
the power supply and the motherboard, but now the two joysticks aren't working
anymore, the system don't recognize them. It recognize correcly the usb
receiver and all the buttons which are cabled to it, instead the two joysticks which
are cabled separately and have two distinct board connected with usb ports seems
dead, except the fact that are receiving the power because the two led on the board
lights up.  At first I tought that the joystick boards have connections to the usb receiver, but as I understand
now, I don't think it work this way, because the receiver needs one connection for every single input,
or so I think after watching some material online. I don't know exactly what type of boards I'm dealing with, so I think
I could misunderstand the general functioning. I attach two photos of the cabinet inside, so if
someone can help me undestand it better or have suggestions to riprstinate it, I will be very
grateful. Thanks

[_Iz-]

The 2 boards the joysticks are connected to look like hacked gamepads (basically the circuit board was removed from a gamepad and the joysticks were wired to them to communicate with the computer).

Does the computer see these gamepads? If you look in control panel / game controllers do you see 2 gamepads there? Does moving the joysticks in test mode show response?