Q: Unusable laptop: CPU throttled to 800MHz with fans running at maximum speed
MBPro Retina, late 2013 running El Capitan
The laptop has been running at constant 800MHz for past couple of weeks. Everything is dog slow to the point of unusable. The fan is running at full speed, 6200 rpm constantly. I have tried,
1. Cleaning the dust by opening the back cover.
2. Removing the whole kernel extensions folder
3. Resetting SMC
Since the most common cause of throttling is usually temps, I installed iStats and checked the reported temperatures from the sensors and discovered something interesting:
Th1H NB/CPU/GPU HeatPipe 1 Proximity -128.0°C Ts0P Palm rest L 32.6875°C Ts0S Memory Bank Proximity -128.0°C Ts1S Unknown -128.0°C TA0P Ambient temperature -128.0°C TBXT Unknown 37.296875°C TB0T Battery TS_MAX 37.296875°C TB1T Battery 1 37.296875°C TB2T Battery 2 34.6875°C TCGC PECI GPU 40.0°C TCSA PECI SA 41.0°C TCXC PECI CPU 39.6875°C TC0C CPU 0 Core 37.0°C TC0E CPU 0 ?? 39.71875°C TC0F CPU 0 ?? 39.96875°C TC0P CPU 0 Proximity -128.0°C TC1C Core 1 38.0°C THSP Unknown -127.0°C TH0a Unknown 36.875°C TH0b Unknown 37.125°C TH0c Unknown -127.0°C TH0A Unknown 36.875°C TH0B Unknown 37.125°C TH0C Unknown -127.0°C TH0F Unknown -13.65625°C TH0R Unknown -44.125°C TH0V Unknown -128.0°C TMLB Unknown -127.0°C TM0P Memory Slot Proximity -128.0°C TPCD Platform Controller Hub Die -128.0°C TW0P AirPort Proximity -127.0°C
Some critical sensors like CPU/GPU proximity and Ambient Temp sensors are reporting a value of -128.0°C. This is probably the reason because from I checked in one of my friends MBPro and these values are reporting normal in their laptop.
Is there any way to disable or fix or write fake values to these sensors? I do not really care about bricking the device since in its current state, it's not of any use.
MacBook Pro with Retina display, OS X El Capitan (10.11.5)
Posted on Aug 8, 2016 11:05 PM