Chosen Solution
Dear Community, I hope you have more ideas than me and you can help me with this :-) Once my Macbook goes into sleep mode, either through closing the lid or by clicking on sleep on the apple menu at the top left corner, the behavior is as follows: After closing the lid it takes around 20 seconds until the MacBook really goes into sleep mode. You can hear that, because the first 20 seconds the fans are blowing slowly, probably to cool the cpu down before going into sleep mode.After this, you can hear that the fans stop and the Mac really goes into sleep mode, but right after the fans start blowing at full power and never stop (even after two days)The fans work perfectly fine while using the mac. Even controlling the fan speed using a dedicated sofware work perfectly fine. Things I tried: SMC Reset (several times)PRAM ResetBoot into Safe modeComplete reinstall of the OSRunning Hardware Diagnostic: Showed no errors Things I noticed: Even if I close the lid on the user profile selection screen (right after boot, before logging on) it happensAfter the Hardware Diagnostic you can boot into a “special” safe mode, where you can only sent the diagnostic results to apple. And it happens even there.The instant I connect the power chord, while in sleep mode, the fans stop. After all of this, I assume it really is a hardware issue. Do you think I can fix it myself? Or what would you do? Unfortunately the MacBook is already out of warranty. Thanks for your support! Thomas Update (01/13/2020) @vhanzl Thanks again for your help. Unfortunately cleaning did no help. Here you can find a picture:
@Thomas Toffalori - Unlike the newer 2018 model which have a T2 chip, yours doesn’t offer this so you do have a means to easily boot up under an external drive. I would see if the problem is still present when you are running off of the external. Create a bootable external drive with the same OS version you are currently using. Using the Option key when you start your system you’ll gain access to the Boot Manager to select the external drive. Let us know if that made a difference! Reference: Mac startup key combinations
