hi alfonso, welcome to gfx.
just quickly glancing at your voltages, it would seem that there is a problem with pin 4 (ground).
this should read as close to 0 as possible, as everything on this path should be being sent to ground.
if you are getting a reading of 8v on this pin that suggests that either the pin or board isn't properly grounded, or that there is a mistake in your readings.
have you missed out the jumper that goes from under pin 4 to ground?
a photo of your board would be useful for further debugging help, but check your board ground connection and that jumper first.
the jumper under pin 4 should join pin 4 to the ground rail (bottom row). and that ground rail (bottom row) should be wired to the ground of the 9v power socket. that is your ground path.
get back when you've checked those things.