[SOLVED]820-2915-a no power, no green light

Status
Not open for further replies.
this board works with a third party charger, found that out when fixing it, but does not turn on with a genuine apple charger, green light comes on for a split second then goes off. my guess is that the U7000
is not recognizing the charger, but im at a loss on how to check what has went out . because the charger wont turn on, all i get is 1-2v anywhere, this board came in with a dead mag-safe, blown f6905, blown off the board c9000. replaced it all and it worked with my third party charger that at the time i didn't know was a third party charger. "replaced the charger with a genuine charger already"
 
wish i had a fake charger still, we got rid of it once we found out it was fake, the customer fried theirs using a fake charger.

i will test voltages at thoes locations tomorrow when i get back into work
 
changed out u7000 with a board that has a bad gpu, but still powers, still nothing, tho i was confused, i removed u7000 and the green light still comes on on the bad gpu board. yet on the board im working on it wont come on. i dont have a fake charger to test it out. what am i missing?

is there a way to test Q7080?
 

dukefawks

Administrator
Uhm, take the board with the bad GPU to Apple for a free repair.....
Get a fake charger for trouble shooting.
 
with or without u7000 i get no 3v42 power , green light for one second then it goes off, and wont come back on unless i leave it unpluged for a few min
 

dukefawks

Administrator
Short on PPDCIN, 3V42? Also remove F7040/41 without U7000 you risk getting the full adapter voltage on PPBUS!!
 
the mac works with a third party charger, at least it did, if i had a short wouldnt it never have worked? it i remove the fuses 7040 and 7041 i shouldnt get any power since PPBUS_G3H would be disconnected to the system.
 

larossmann

Administrator
Staff member
Remove F6905. Place 18.5v from a real bench power supply on pin 2 of F6905. Then plug known good 85w charger in with known good dc in board. If it works, Q7080 is bad.

If you do as duke says and get a knockoff charger this will be easier to troubleshoot.
 
ok so even putting in 18.5v in on pin 2 of f6905 and plugging in the 85w apple charger, did not give a green light. i do have a fake charger on its way, praying its fake, spending less than 20$ on it and it has no apple logo. lol, is their any more testing i can do before the new charger arrives?
 
ok got the fake charger, ppbus_h3h is 12.56. what else should i check?
R7005/21/22 all have power, r7005 is 18.5, r7021 is 19.03 and r7022 is 19.03
 
Last edited:

dukefawks

Administrator
Not really, you can remover the gate resistors and then test if both FETs open and close. Check on youtube how to test a FET. The gate needs to be disconnected from everything to do that.
 
awesome well next time ill have an idea how to test that little package. thank you, can i get you to close this thread please and thank you for all your help
 
Status
Not open for further replies.
Top