820-2850 green light no boot no fan spin ppbus_g3h 4v

protocold

Member
U7000 - 27/28 is 20.6 ohm. 17/18 resistance is 47 ohm.

pin 2 16.4v
pin 3 3.95v
pin 6 3.3v
pin 7 0.65v
pin 9 0.05v
pin 10 3.3v
pin 11 0.03v
pin 12 3.4v
pin 13 3.4v
pin 14 3.2v

pin 17 4.07v
pin 18 4.07v
pin 19 5v
pin 20 5v
pin 21 0.12v
pin 23 4.07v
pin 24 4.09v
pin 25 8.47v

pin 27 16.28v
pin 28 16.28v

where should I look?
 
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2informaticos

Administrator
Staff member
Check the R/C networks from pins 5, 7, 8.
Check/replace C7025.
Resolder entire ISL6259 area (surrounding components too).
 

protocold

Member
i think i accidentally touched something and blew up the ISL6259... pin 7 and pin 8 are now shorted to ground... ;/
 

2informaticos

Administrator
Staff member
SCL/SDA lines are easy available at battery connector.

Try, always when possible, to measure touching surrounding components of QFN chips.
Not a good idea to touch directly chip pins; is very easy to make short...

Yes, replace possible.
Before applying power, check no short present on board.
Pay atention to Q7030/35.
 

protocold

Member
pin 2 16.4v
pin 3 3.95v
pin 5 1.1v
pin 6 3.3v
pin 7 0.8v
pin 8 1.35v
pin 10 3.3v
pin 11 0.03v
pin 12 3.4v
pin 13 3.4v

pin 16 3.5-4.5v cycling (measured at C7026)
pin 17 8.15v
pin 18 8.15v
pin 19 5v
pin 20 5v
pin 21 0.27v
pin 23 8.22v
pin 24 8.35v
pin 25 12.58v

pin 27 16.28v
pin 28 16.28v
 

protocold

Member
how do i fix it?

Also, how come yesterday I was getting ppbus_g3h at 12.2v below i blow the ISL6259 and now after replacement it is 8.1v?
 

2informaticos

Administrator
Staff member
Maybe bad ISL, or solders.
Check diode mode on SCL/SDA lines, w/ and w/o ISL6259 soldered.
Be sure R5280/81 are both good.
 

protocold

Member
i checked pin 2 of D6950 is shorted to ground...i removed it to test, doesnt help.

I also removed C6953 to check, doesnt help.

Bad SMC?
 
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