hi i have a macbook a1398 the fans run at high speed and the laptop is very slow.and the serial no says serial no unavailable.has anyone got this problem.
thanks

Hello this is normal situation when serial number is unavailable, try write new serial number on your EFI or replace EFI chip with serial number from another board (you can buy dead board or EFI chip on eBay )

hi
i have put a new efi chip still same problem says s/n unavailable also tried to write it with serializer program and that also was unsucessful. Anymore i can check on this board.

okay so i used a clean bios with clear me i have the serial no showing now ,but still fans full speed and also do diagnostics i get an error smc failure PFM0006.I guess something with the smbus lines of emc1414 and sensors.can any one tell me which sensor line has failed in the thermal section
thanks

today changed the smc chip still same problem.the camera connector is damaged will that make a difference.

hi all
so now my istats report gpu therm diode digital and analog gpu die also proximity gpu therm absent not reading temp of the gpu.also my camera cable is bad will that also make fans spin fast and make laptop sluggish.
thanks

hello
finally fixed the laptop there was a a track break from smc smbus to emc1414 r5350 r5351.now the gpu therm detects the temp and fans run normal speed no lag.
thanks all again