powerbook 12" trackpad non functioning

Just bought a very late 2006 1.5 powerbook 12". The trackpad was non-functional when I bought it. I replaced with a warranted functional top case (trackpad) and still not functioning. The connector seems solidly soldered to the logic board and the connector doesn't seem loose. External usb mice work fine. Any way to test? Computer boots and runs fine in all other respects.