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NO CPU temperature reading on and off, logic board faulty?

I noticed my MBP had been really slow lately sometimes, the problem got worse and worse overtime. Kernal_Task has been using up the CPU even without any loads. I thought my MBP was dirty, so I opened it up and found the battery expanded very badly, although it only had 20 cycles over 3 years of usage. Trackpad was very stubborn and I had been wondering why, the battery crooked the frame.

I went ahead and bought a replacement battery and had it replaced. The problem is still there.

I noticed when this happens, CPU Temp from Core 1 - 4 are disappeared, as well as CPU PECI and Intel GPU.

As soon as the temp readings come back, kernal_task goes back to normal.

Did the expanded battery cause damage to the logic board ?

Is a repair even worth looking into?

Update (10/15/2016)

I've tried resetting the SMC several times, still the same result.

I just took it apart, will re-apply thermal grease tomorrow and see what happens.

with the new 2016 MBP refresh coming around the corner, i just want this MBP last a little longer.

Update (10/16/2016)

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Here are the screenshots of the temperature readings.

Answer this question I have this problem too

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[image|914064]

[image|914068]

[image|914067]

See the temp reading, at first it's stuck at 95F while the CPU proximity is much higher.

I had the system loaded up to 100% with multiple apps and videos playing, it's still at the same temp.

Then see 2nd screenshot. Temp readings disappeared.

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It does sound like your systems logic board is in trouble here. Did you spill something into it or sit it down on a wet surface?

I would install this app so you can better monitor whats happening here with the thermal sensors: TG Pro for less than $20 US its worth it! Post a screenshot of the main screen so we can see what its' telling you.

In the meantime I would strongly recommend you make a good backup if you haven't yet as well as prepping up a bootable USB thumb drive with the OS installer copied to it so you have a lifeline just in case.

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I just bought a Mac Mini to use for now.

I never spilled anything on it, the MBP has mostly been used as a desktop with Apple display since new. I've travelled with it less than 10 times. It rarely got exposed to anything outside my office. I remember last time I was in Mexico a few weeks ago, the track pad got really stubborn and hard to press. It was the battery. Maybe the high elevation in Mexico contributed to the battery expansion?

I posted screenshot of iStat instead, without even needing TG Pro for logging, it's pretty clear the sensors are malfunctioning.

I also noticed the CPU Package Core sometimes would shoot up to almost 300watts , which is impossible. and sometimes it has no reading.

Is this indication of a faulty SMC or CPU? either way I have to get a new logic board?

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Lets do this boot up under an external drive see if that makes a difference.

I prefer TG Pro as it offers a real time and high water mark, that way if you don't get the snap at the high point you still have it. Logging can also be very helpful as you can import into a spreadsheet.

As to the sensors them selves malfunctioning, I doubt that, they appear to be working just fine here. Yes, they are running hot if these are in Cº or in Fº which they are not to bad.

If you can isolate out the drive by using an external as the boot drive that should tell us whats at fault here.

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The temp are in F.

If you see my screenshots, why did the temp readings disappear on the CPU cores? They sometimes would disappear for a few minutes, or a few seconds. Is this a normal behavior?

I doubt the drive has anything to do with it. I tried multiple format / reinstall too. The OS is not the issue. The drive is fine.

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Sorry I wasn't clear here. What I meant was SMC was working as all of the other sensors are AOK.

The action of using an external drive was to remove a bad OS install. If you fully wiped the drive when you installed the OS then we know you removed any suspicious software.

The CPU sensors are within the chip die, At this point you'll need to replace the complete logic board. You really can't replace the CPU alone here.

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The OS shouldn't affect it. What you're reading is data direct from the system bus, therefore any issues will be from the CPU, as the other sensors work fine (i.e. proximity).

Do the fans still kick in under stress or do they remain at a low speed?

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I have had issues before with the fan/temperature before, try resetting the SMC:

  1. Shut down the computer.
  2. Plug in the power adapter.
  3. On the built-in keyboard, press the Shift, Control, and Option keys on the left side and the power button, all at the same time.
  4. Release all three keys at the same time.
  5. Turn on the computer.

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To reset the SMC this is the correct sequence of keys: Reset the System Management Controller (SMC) on your Mac.

Here is a full listing of the startup key options: Startup key combinations for Mac

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What you've provided is exactly the same thing I've mentioned (Apple website: https://gyazo.com/744b8d4fa62f3f1496029b...) . Not sure what you're trying to say here? If you mean that nothing happens, thats because there is no on screen prompt to indicate it has been reset.

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