Take off the 5 screws on the bottom and carefully slide off the back assembly.
Take a voltage probe with the clock plugged in and check the power supply. By following the power wires into the PCB. The power solder joints should be above 5v even with a phone plugged into the usb charger.
Next i noticed that there was some kind of transient voltage across the back buttons of a few 100mV. This is incorrect. I tried to measure the current of one button to see if i could put the computer under an artificial button press. Next i noticed a different button came to 3.333V which is correct . I pressed it and it registered on the screen. Slowly but surely after I pressed the button with 3.333V others returned back to their proper voltage. Now all my buttons work.
This indicates ,to me: extreme static/noisy electricity, bad voltage regulators, or a weak capacitor somewhere.