Hello guys,
I have a imac 21.5 2012 (820-3302) with some weird issues, i will try to do my best to explain clearly (btw sorry in advance for my terrible english).
First, L9100 has blow up, i think because of the lcd cable that wasn't properly pluged (shorted, changed him).
I replaced L9100 but then, the fan was always at full speed enabled even if the imac was turn off. I read on the board that q7950 was probably the problem, i changed it and after the imac was ok.
I didn't used it only one day, i tried to turn him on but nothing, only led 1, i changed q7950 (q7950 not new) again and he managed to turn on, but after that, dead again, same thing, again after 1 day that i didn't used it.
Since, i again changed q7950 by another one but it never turned on again. Tried even a brand new q7950 but nothing, only led 1.
So i tried to change U7950, U7870, Q7870 (all are news), U7950 have a weird voltage, Q7870 and u7870 too :
U7950 :
Pin 1 = 12.16v
Pin 2 = 3.3v
Pin 3/4 = 0V
Pin 5 = 12.16v
Pin 6 = 19.20v
Pin 7 = 12.16v
Pin 8 = 12.00V
Q7950:
Pin 1, 2, 4, 8 = 12.16v
Pin 3, 5, 6 = 12.16v
U7870:
All good except
pin 7 = 19.22v
pin 8 = 3.8v
Q7870:
All good exept
Pin 4 = 19.22v
I also noticed that U5300 have pin 6 17v.
Big thanks in advance for your help.
I have a imac 21.5 2012 (820-3302) with some weird issues, i will try to do my best to explain clearly (btw sorry in advance for my terrible english).
First, L9100 has blow up, i think because of the lcd cable that wasn't properly pluged (shorted, changed him).
I replaced L9100 but then, the fan was always at full speed enabled even if the imac was turn off. I read on the board that q7950 was probably the problem, i changed it and after the imac was ok.
I didn't used it only one day, i tried to turn him on but nothing, only led 1, i changed q7950 (q7950 not new) again and he managed to turn on, but after that, dead again, same thing, again after 1 day that i didn't used it.
Since, i again changed q7950 by another one but it never turned on again. Tried even a brand new q7950 but nothing, only led 1.
So i tried to change U7950, U7870, Q7870 (all are news), U7950 have a weird voltage, Q7870 and u7870 too :
U7950 :
Pin 1 = 12.16v
Pin 2 = 3.3v
Pin 3/4 = 0V
Pin 5 = 12.16v
Pin 6 = 19.20v
Pin 7 = 12.16v
Pin 8 = 12.00V
Q7950:
Pin 1, 2, 4, 8 = 12.16v
Pin 3, 5, 6 = 12.16v
U7870:
All good except
pin 7 = 19.22v
pin 8 = 3.8v
Q7870:
All good exept
Pin 4 = 19.22v
I also noticed that U5300 have pin 6 17v.
Big thanks in advance for your help.