Original post by: originalmachead ,
'''Not much to go on''' so '''I'll guess liquid spill damaged''' them, but not the power on button. Open and examine for corrosion and/orburned components... check ribbon cable(s) connections ''(might be updside down or not in far enough/locked down completely)''. If the cable and logic board look good replace the top case. ''If this Answer is helpful '''please remember to return and mark it '''Accepted.''