820-3115

Sjenja

New member
SMC_PM_G2_EN switching on and off every 0.5 sek or so. Clock chip is ok getting the 32Khz and the 25Mhz. What should I look for more ? No signs if water damage on the board. Anyone had this problem before?
 

larossmann

Administrator
Staff member
either bad U7200, bad SMC, or bad U7941. Even though there is a resistor inbetween U7941 and U7200 if U7200 is bad it can drag that down.
 

Sjenja

New member
Ok, found that SMC was bad, after changing that had the computer working for 5min then U7400 fried the CPU. :(
 

Sjenja

New member
On another note had the same problem on an air 820-3437 replaced U7501(U7200 equivalent on 3115 ect.) and it worked so not always the SMC. So its easy to desolder the U7501 and see if the SMC_PM_G2_EN signal becomes stable.
 

larossmann

Administrator
Staff member
same thing as what i said, u7200 on an a1278 is u7501 on a newer a1466. it can pull down the signal from the smc. i always try the latter before the smc because it is easier to put back on :)
 
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