Hi my name is ***** ***** I will do whatever I possibly can to help you with your issue.
Do you know the spec of the MacBook Pro, which model it is?
Does it have a sealed in battery, or one you can remove?Have you tried any troubleshooting steps already?
Thanks in advance.
Then I would begin by resetting the power management unit, I will give you the steps.https://support.apple.com/HT201295
To reset the power management you need to simultaneously press and release the (left side) Shift-Control-Option keys and the power button., and simultaneously release them.
You need to know that you are pressing these buttons and the power button at the same time, and that it does not power on if you press them at the same time.So if you try this step, and you hear the machine power on, you know you haven't pressed and released the keys and power button together at the same time. You will need to power it off and try it again if that happens.If you do it right it will not power on or do anything at all to indicate that it was done right. You will then wait 5 seconds and press the power button on it's own to power it up and check if this has resolved the issue.
Ok, this could be a hardware issue needing a hardware repair technician to look at it to diagnose the part that needs to be replaced.
You can try resetting the PRAM, as this stores the brightness setting.https://support.apple.com/HT204063
You need to hear two startup chimes to know this has been done properly.
As long as you have no external devices connect, and you've tried both these steps, then there is nothing else besides hardware diagnosis of the problem that can be done I'm afraid.
It would be different if you could see that error message again, or if something changed to get you to any type of startup screen.
You're very welcome!You know I still think you need to reset the NVRAM as in that article, because it can fix a whole host of things that are not just related to the brightness.
Have you tried the NVRAM reset where you heard two startup chimes from the MacBook Pro? And if so has it still not made any difference?
If you have, and you do need to take it to a service technician, you should check if you still have warranty cover or extended AppleCare.If you're getting a paid repair you should get it done by an authorised service provider, because the repair will come with it's own warranty of 90 days.You can search for them here http://locate.apple.com
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