lenovo b470 turns on only on battery

[String2016]

Re: lenovo b470 turns on only on battery

pr4001=202.8kohms

[String2016]

Re: lenovo b470 turns on only on battery

here is the photo i start measuring on the upper as pin 1

[String2016]

Re: lenovo b470 turns on only on battery

you are right as i checked on the schematic pin 6 has 19v and pin5 has 3.3v pin 4 is connected to the ground but pin 1-3 is beeping to the ground could it be shorted?

[qayyum786]

Re: lenovo b470 turns on only on battery

Change pq4001
or remove it and just jumper from pin 4 to pin 3

[qayyum786]

Re: lenovo b470 turns on only on battery

Remove pq4001 and
jumper as i have shown in image

[qayyum786]

Re: lenovo b470 turns on only on battery

You get confused during counting the pin of pq4001
now
just let me know the voktage of pu4001 voltages of source - gate - drain
pin 1,2,3 = ?
Pin 4 = ?
Pin 5,6,7,8 = ?

Please don't make mistakes during measuring the voltages on pin

[Moammad]

Re: lenovo b470 turns on only on battery

Hi
check PR4006 voltage before and after resistor
its connect direct to your +Ad and your pin2 of bq

[qayyum786]

Re: lenovo b470 turns on only on battery

ACIN is 2.6 v
Please Check #8
That means PIN 2 ACIN volt is perfect for BQ24745
Thanks @MOHAMMAD for your support

[String2016]

Re: lenovo b470 turns on only on battery

@qayyum786 pu4001 here it is ive measured again
pin 1,2,3 = 19v
Pin 4 = 6.58v
Pin 5,6,7,8 =19v

[qayyum786]

Re: lenovo b470 turns on only on battery

That means PQ4001 & PU4001 both are ok
Remove PU4002 and check with adapter only
Dose laptop power on with adapter after removing PU4002

[String2016]

Re: lenovo b470 turns on only on battery

removed PU4002 plugged in charger only laptop cannot power on

[String2016]

Re: lenovo b470 turns on only on battery

I noticed alson that no voltages on DRAIN of pu4002 and on pr4005 it has only 10kohms on the schematic supposed to have 470k

[qayyum786]

Re: lenovo b470 turns on only on battery

When you masure VOLT ON DRAIN before removing PU4002
Or masure it after removing PU4002

[qayyum786]

Re: lenovo b470 turns on only on battery

Change

pr4005
pu4002
pu4004
pu4005

[String2016]

Re: lenovo b470 turns on only on battery

when i measured the pu4002 with in the board and removing its the same measurement no drain voltages

[qayyum786]

Re: lenovo b470 turns on only on battery

Yes afcors if you check voltages WITHOUT BATTERY

& iCHARGER PLUG IN you will not get any voltages on DRAIN
DRAIN is connected to the BATTERY SIDE

Do you know how to test MOSFET FOR SHORT
If yes than REMOVE CHARGER & BATTERY BOTH and masure
pu4002
pu4004
pu4005
I guess 1 of them is shorted

[String2016]

Re: lenovo b470 turns on only on battery

check on diode mode on pu4004 black probe on source and red on drain it has 0.200v and on pu4005 it has 0.500v pu4002 0.465v

[String2016]

Re: lenovo b470 turns on only on battery

with charger plugged in pu4004 drain have voltage but source no voltage PU4005 both drain and source no voltage

[qayyum786]

Re: lenovo b470 turns on only on battery

All 3 mosfet check out side of motherboard
if all 3 fet is ok than bq ic is victim

[String2016]

Re: lenovo b470 turns on only on battery

you mean i pulled out the 3fets and check outside motherboard?