This topic was opened a long time ago, I am writing this in case it might be useful for a friend. I have been dealing with the same problem for days, these models give the LED bounce error 2 times when there is no speaker connected. Please connect a speaker. Or, to perform the operation with the lid open, connect a 4.7ohm resistor to the speaker outputs, the system will perceive these resistors as speakers, so the device will not give this error.