[FUBAR] LB 820-2879 B no green or orange light (needs SMC)

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Mac-N-Sauce

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ok, i replaced the u7000(ugh that was hard) you make it look so easy. I am jealous. I now have 3.18v on pin 14 and up on pin 1 and 2 of u6901 but no 3.42v on pin 4. Is my pin 14 too low or my u6901 garbage?
 

Mac-N-Sauce

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ok, first i have attached some photos for you guys to have a good laugh! Louis you have nothing on me when it comes to bad soldering!
Second, I now have 3.36v on u6901 pin 5. i followed the path on the diagrams you sent, still no green light. i have 4v on pins 17,18 for u7000
I need the 12v ppbus_g3h
 

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larossmann

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Dude that is fucking scary. You need one strand of wire for this!!! Why do you think they call it the onewire circuit :p

You have 3.36v on pin 5, but what about pin 4? Is it outputting voltage now?

U6901 is a logic gate that, when SMC_BC_ACOK is present, will allow PP3V42_G3H to pass to output. The idea here is that it will power U6900 which allows the charger to talk to the SMC if the ISL6259/U7000 says that it is ok for it to. So follow to the next logical step - is U6900 getting 3.4v? Is U6901 shooting out 3.4v for U6900? If not, why?
 

Crizz

Member
You use a coax-cable from a mic or webcam for the jumper... try to use a wire from a dead battery!
 

Mac-N-Sauce

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I have 3.36 v on pin 4 and 5 of u6901 and pin 1 of u6900 and on pin 4and 5 of u6900 its 3.36v as well. I guess thats why i am confused. I jumped a wire to the u6901(although poorly done) to get my 3.4v to pin 5 and it appears to be getting to u6900
 

Mac-N-Sauce

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Just wanted to show a better job of adding the wire. What is the product you use to insulate the wire? Green light on charger in picture 3! So we now have one wire, but no orange with battery connected.
So off I go to this one. I only have 4v on the charging circuit. Also can not power on with power pads
 

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larossmann

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circuitworks cw3300g is good for me. it looks like you have a green light, or is that just the flash?
 

Crizz

Member
If your PPDCIN is 18.5V but PPBUS_G3H is only 4.57V there is maybe something pulling it down! YES
Probe with your fingers if something is getting hot.
Desolder F7040 and measure the voltage on pad1 of F7040
Are you able to inject 12V to PPBUS_G3H with an external power source?
 

Mac-N-Sauce

New member
i pulled the fuse and had same 4.57v on pin 1, changed the 6259, now i have 15.5v at the fuse, q7030 pin 5 is 16v and pin 4 is 18.4v
so i have gone from too low, to too high
 

Mac-N-Sauce

New member
Ok, I am having a hard time with the isl, lack of experience. The components are so close around it making it difficult to clean up pins. I just watched one of your videos where you had a large solder ball on the center pad of the isl. then you pressed it down to squeeze it out. I am using the curve tip. Should I switch to a straight point to clean it up after?
 
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