CPU i5 3,1GHZ Throttled to 1.6GHZ
So i tried to replace my i5 2400 3,1 GHZ CPU with a i7 3770 it did not work. I reinstalled the i5 2400 and everything worked normal except the Fans for ODD and CPU. Well i thought no problem i will regulate it with software. But then i experienced a big drop of perfomance in OBS and Logic. I installed intel Power Gadget and noticed the CPU Frequency is locked to 1.6GHZ.
The Apple Hardware-Test says: 4SNS/1/C0000008: TLOp--124
I searched in the Web and found that it must be a Temperature Sensor connected to the LCD.
1. SMC PRAM VRAM Reset
2. I ordered a new LCD Tempsensor - replaced it but nothing changed.
3. I ordered a new V-SYNC /TempSens Cable (connected to the LED Backlightboard) nothing changed.
4. I ordered a new LCD Data Cable - nothing changed.
5. I ordered a new Logic Board + CPU - nothing changed.
So these are the steps I did until now and I don't know what to do now...
The only thing left i could imagine would be the LED-Backlightboard maybe reinstall OS or could be something wrong with the EFI, Powermangament I dont know.. Maybe someone experienced the same issue or knows how to repair it.
Everything else except Fans going wild and CPU is throttled works well.
EDIT: (This Programm is called HW-Monitor and is the only one that shows me 128° on LCD)
So i was away for like 2 hours and the imac was in Sleepmode when i came back i saw this:
Sadly it went back to 1.6GHZ after a short period of time.
So its definely reproducable. I have to put the iMac in Sleepmode for 20-30secs and when i wake it up the CPU runs normal ant turns to 1.6GHZ after 10secs. What the !&&*...
Maybe another hint. When I turn on Sleepmode the fans are stopping. NOW when i wake up the MAC TGPro is showing my some N/A Temperatures:
Platform Controller Hub DIe
As soon as these both Temperatures are availabe the Fans power up and the CPU gets throttled.
Tried to reinstall OS X did not help..
Tried to run the iMac without the LCD on a second Monitor did not work.
When i opened the iMac i noticed strange "glue" on the poweradapter:
Also i run a SystemDiagnosis which gave me the same error as the AHT:
This week i will probably bring it to an Authorized Apple Reseller and hope the can help me.
Is this a good question?