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On a Late 2008 MacBook Pro with a dead battery, i have a SMC issue that popped out. My fans are at 100%, no keyboard backlit, the usual SMC story.
I have this error in dmesg.
I've tried the usual technique from the Internet to reset the SMC, but no success.
Any other ideas ?
Does your laptop actually boot macOS? If not can it boot into Safe Mode?
Here is an Apple article with instructions for resetting the SMC:
http://support.apple.com/kb/HT201295
Can you run the Apple Diagnostics or Apple Hardware Test (the latter should be on the second DVD which originally shipped with the laptop)?
If your laptop will not power on, then disconnect the battery and try powering on the laptop using just the charger.
If the laptop is booting and you have the fan(s) running at high speed, then some sensor is likely not being recognized. If your battery is bad, then most likely the temperature sensor on the bad battery is not being recognized. Apple hardware will run the fan(s) at high speed whenever any temperature sensor is not working correctly in order to protect the Mac from overheating.
Does your laptop actually boot macOS? If not can it boot into Safe Mode?
Here is an Apple article with instructions for resetting the SMC:
http://support.apple.com/kb/HT201295
Can you run the Apple Diagnostics or Apple Hardware Test (the latter should be on the second DVD which originally shipped with the laptop)?
If your laptop will not power on, then disconnect the battery and try powering on the laptop using just the charger.
If the laptop is booting and you have the fan(s) running at high speed, then some sensor is likely not being recognized. If your battery is bad, then most likely the temperature sensor on the bad battery is not being recognized. Apple hardware will run the fan(s) at high speed whenever any temperature sensor is not working correctly in order to protect the Mac from overheating.
I've run AHT from that repo for my laptop ( MacBookPro5,1 Mac-F42D86A9 ).
So, regarding backlit that doesn't work and my fans that are blowing, i will reiterate from English to English, again.
Question: What does SMC handles and is responsible for ?
Answer: The SMC is responsible for these and other low-level functions:
Ok, so, i do have all the above issues, plus, i have a that dmesg print saying:
SMC is in U mode, not in A mode
Question:
Are fans blowing fast due maybe to a bad sensor, as you said, and the keyboard backlight not working due to a liquid spill, as you also mentioned ?
Answer:
No, those problems are strictly related to the SMC issue.
So, how do i put it back in Mode A ?
It boots. It doesn't enter Apple Diagnostics if i press D, maybe because i've install rEFIt ?
Until now, each time i've had the SMC problem, the only working solution for my was: Left **** + Option + Ctrl + Power.
Now, if i use that technique, the notebook shuts down and the only way to start it again is to Press PWR 10 seconds without the power cord, 10 seconds again with the power cord plugged in, and then a simple push of Power Button.
CoieMici wrote:
It boots. It doesn't enter Apple Diagnostics if i press D, maybe because i've install rEFIt ?
If your Mac shipped from the factory with an OS Restore DVD, then the Apple Hardware Test will be located on the second DVD. If the Mac did not ship with DVDs and you've modified the contents on the original hard drive or replaced the hard drive or reinstalled macOS, then you will no longer have access to the diagnostics stored on the drive from the factory. I don't rEFIt itself interferes since the key command is firmware based.
Until now, each time i've had the SMC problem, the only working solution for my was: Left **** + Option + Ctrl + Power.
Now, if i use that technique, the notebook shuts down and the only way to start it again is to Press PWR 10 seconds without the power cord, 10 seconds again with the power cord plugged in, and then a simple push of Power Button.
If you must perform an SMC Reset each time, then most likely you have a hardware issue with the SMC chip which will require a hardware repair.
No, until a week ago until, when i had to perform a SMC reset i used that command.
Q:When i had to perform SMC reset ?
A: When the laptop ran out of battery, so i was pretty careful to have the cord plugged-in at all time. So i didn't performed SMC reset every day.
Present day: Same SMC reset command brings my laptop in the state that i've described above: only starts if i long press the power for 10 seconds without .... bla bla
A bad battery or even just a completely discharged battery can prevent an Apple laptop from powering on or even charging. I've had older Apple laptops have "trouble" powering on when the battery is removed. In those cases I have had to either press the power button several times or holding the power button a few seconds longer for the laptop to power on with just the charger. You may need to wait five or ten seconds after connecting the charger as well.
I'm a bit concerned about no keyboard backlight as that is something I rarely see fail except for liquid damage (the majority of my repairs are for liquid damage), but there is a slight chance the cable could be loose. The fan(s) running at high speed do indicate a bad sensor somewhere (possibly battery though). See if you can find the correct Apple Hardware Test from here:
https://github.com/upekkha/AppleHardwareTest
I should also mention that you may want to consider using rEFInd which I think is a more updated version of rEFIt. If you are using Linux I see it is available in the Debian repositories as well so it may be available in other distros as well if you are using Linux.
CoieMici wrote:
So, how do i put it back in Mode A ?
By replacing the bad SMC or replacing the Logic Board. Keep in mind replacing the SMC chip does not guarantee it will work since there may be some other problem on the Logic Board affecting the SMC chip. This is the best anyone without physical access to the system can do for you.
SMC is in U mode, not in A mode
