820-00281a power cycle with battery. slow 20v

BoKKeR

New member
Not a company just doing this as hobby project.

a1707 was stuck on 5v, I replaced c6906 and c6905 caps, because of my bad soldering I had only soldered the c6905 cap on one side, but this made the board run on 20v. It turned on works fine, when connecting battery and the battery ribbon it would just power cycle on when reaching 10v.

I resoldered the c6905 cap. Now I have a board that struggles :

20v only kicks in after a while.


cap connected: (5v for good 2 minutes)
PPVIN_G3H_P3V3G3H: 3.8v
PPDCIN_G3H_CHGR_R: 5v
PPBUS_G3H_R: 0.6V

(20v stage)
PPVIN_G3H_P3V3G3H: 20v

20v takes time to kick in, sometimes minutes. When I connect the battery ribbon the board power cycles the second the voltage reaches 10v, and power cycles over and over. The laptop works without a battery but I specially bought a new battery from ebay as the old one was bulged up.

I ripped the d6902 pad but I soldered d6902-d6906-d6905 together as they are on the same ppvin_g3h_p3v3g3h rail.
 

2informaticos

Administrator
Staff member
Can you post 820-xxxxx code?

Do not trust new chinese batteries.
Try to get an original old one, just for test.
 

BoKKeR

New member
820-00281a. seller claimed the battery is OEM, but it seems to be chinese OEM, I will look if I can find something else.
 

BoKKeR

New member
I had the seller send me a free replacement. Anything more I can measure while I wait for it to arrive?
 

BoKKeR

New member
got the fake battery and a macbook top with a used old battery. before I had chance to test any of it I realized that the 20v is not kicking in without the battery anyways.

ppvin_g3h_p3v3g3h is 3.6v
u6903 enable is 4.5v
SMC_RESET_L and BUF_SMC_RESET_L = 3.4V
PP3V3_G3H_REG_R= 3.418 v
PPBUS_G3H_R 0v
PPBUS_G3H 0v
PPDCIN_G3H_CHGR_R = 5.197 v
PP1V8_UPC_TA_LDOA 1.8v
PP1V8_UPC_TB_LDOA 1.8v
PP1V8_UPC_XA_LDOA 1.8v
PP1V8_UPC_XB_LDOA 1.8v
 

2informaticos

Administrator
Staff member
Check if R6920 has 0 ohm; post its voltage too.

"ppvin_g3h_p3v3g3h is 3.6v "
Post diode mode to ground.
 

BoKKeR

New member
R6920 is 0.8ohm, both sides are identically 3.4v

I get open circuit on ppvin_g3h_p3v3g3h, thats the part where I was soldering...

I wonder if I blasted the 2.2UF 20% 35V X5R capacitors when soldering them
 
Last edited:

2informaticos

Administrator
Staff member
"PPDCIN_G3H_CHGR_R = 5.197 v
------------------
R6920 is 0.8ohm, both sides are identically 3.4v"
Look at schematic and post accurate information.
 

2informaticos

Administrator
Staff member
"ppvin_g3h_p3v3g3h is 3.6v"
Still the same?
If yes, chgange the diode...

"Post diode mode to ground."
If you have time...
 

BoKKeR

New member
ppvin_g3h_p3v3g3h still 3.6v
diode mode to ground is 0.55v from all 3 pins of d6902 before change

I will source and replace the d6902 BAT30CWFILM and report back
 

BoKKeR

New member
Replaced D6902,

It made 20v work without battery, with battery it still power cycles :(

I just want to remind you that I destroyed the pad under pin3 as mentioned in the first post, so I had to wire
D6902 pin3 <-> pin1 c6906
D6902 pin3 <-> pin1 c6905


Measurements:
D6902
pin1 20v
pin2 12v
pin3 20v

and its 0.5v from D6902 pin1,2,3 to ground

c7042 pin1 (ppcdin_g3h_chgr) is 20v.

c6905 pin1 20v
 
Last edited:

BoKKeR

New member
The laptop boots with charger alone, it's usable. I can login etc

But with battery it keep cycling between trying to go from 5v to 20v (my meter says it dies on 10v)
 

BoKKeR

New member
Yes I have tried with the used known battery that came glued in with a top case, and 2 ebay batteries. They all have the same problem. It only happens when I connect the ribbon so it might be a lithium security cutout?
 
Top