overshoot
Member
Hi,
I have that 820-3332 which came apparently only for a GPU issue as it was getting no pictures.
Customer also told me the computer would sometimes shutdown but he thought it was the battery.
So I re-did the joints around U8900 and reflowed the area and then got a picture.
However once I booted to the OS I could hear the fans spinning full speed.
System was laggy as for a sensor issue.
Running Mac Fan Control I could see the PECI GPU, PECI CPU and the core sensors jumping from 60 degrees celsius to a 100 which would correspond to the fans spinning up faster.
What I have understood is that PECI_CPU is a bidirectionnal line which talks to the SMC.
PECI_GPU is the internal Intel GPU so everything comes from the CPU.
I then run ASD EFI 155 on it to check the sensors but all sensors passed the test.
I also did run ASD OS 155 also for the sensors and again, all tests passed.
These jumps in reading seems intermittent and system runs normally to laggy from time to time.
I did replace the SMC but it didn't fixed the issue.
I've checked some reading around Q5030 but they are equivalent to a good working board.
I have replaced every component between this PECI_CPU line and the SMC, just in case, but same thing.
Remaining is CPU... System seems to be working just fine but with this sensor failing, it becomes unusable.
Is there any fix to this?
What a waste to throw the board just for a sensor issue...
In SMC bypass the system runs ok.
I have that 820-3332 which came apparently only for a GPU issue as it was getting no pictures.
Customer also told me the computer would sometimes shutdown but he thought it was the battery.
So I re-did the joints around U8900 and reflowed the area and then got a picture.
However once I booted to the OS I could hear the fans spinning full speed.
System was laggy as for a sensor issue.
Running Mac Fan Control I could see the PECI GPU, PECI CPU and the core sensors jumping from 60 degrees celsius to a 100 which would correspond to the fans spinning up faster.
What I have understood is that PECI_CPU is a bidirectionnal line which talks to the SMC.
PECI_GPU is the internal Intel GPU so everything comes from the CPU.
I then run ASD EFI 155 on it to check the sensors but all sensors passed the test.
I also did run ASD OS 155 also for the sensors and again, all tests passed.
These jumps in reading seems intermittent and system runs normally to laggy from time to time.
I did replace the SMC but it didn't fixed the issue.
I've checked some reading around Q5030 but they are equivalent to a good working board.
I have replaced every component between this PECI_CPU line and the SMC, just in case, but same thing.
Remaining is CPU... System seems to be working just fine but with this sensor failing, it becomes unusable.
Is there any fix to this?
What a waste to throw the board just for a sensor issue...
In SMC bypass the system runs ok.
