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Macbook A2442 (820-02098) Stuck at 20V 0 Amps

Instafixx

Instafixx

Active member
Customer said the device was on but not charging. When it came to me it wasn't turning on - maybe battery drained.
It is first drawing 5V and .540 amps and then unplug and replug the charger it is drawing 20V and 0 Amps. This is the behavior in all 3 USB C ports. I get haptic on the trackpad as well. This finding is with everything connected as this device wont turn without a battery.

I scan the board for any corrossion or thermal heat - but none.

PPBUS is 12V(without battery).
3v8_AON
PP3v3_LDO
P1v8_s2
All are present.
CC1/CC2 lines are okay.

Slight heating at U5200 that too after keeping the charger connected for quite some time. Replaced it. Still the same.
DFU revive gets stuck midway at "Installing Software". - It didnt go to DFU mode via the keyboard method - which was strange. I had to jumper.

Check Diode Mode at JT400 and JT5151. All are okay.
 
Instafixx

Instafixx

Active member
With a charged battery i did a DFU revive. This time i get logo on screen and loading bar with Host mac still halfway at "installing Software" the target mac was on and not charging.
Didnt enter DFU with KB and had to jumper it.

With Device on andCharger Connected (20V and 0 Amp Draw)

CHGR_PHASE1/2 0V
PPDCIN_AON_CHGR_R 0V
PPVBAT_AON_CHGR_R / PPBUS 11V
CHGR_BGATE 3V

Without Battery (5V and .100 Amps)
PPDCIN_AON_CHGR_R 5V
PPVBAT_AON_CHGR_R / PPBUS 12V
CHGR_BGATE 3.5V
CHGR_PHASE1/2 1.8V


Confirmed that its not a battery issue. Other logic board on this Chasis works perfectly fine.
 
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2informaticos

2informaticos

Administrator
Staff member
Looks a bit low for me; compare with good board.
I expect 0.300-400 reading.

I had one A2681 which started working randomly.
It had 0.110-145 diode mode reading.
Injecting 4-4.2V for some minutes made it starts; only U8100 showed a bit of heat signature.
After some time didn't start again...
 
Instafixx

Instafixx

Active member
But the point here is all voltages are present without battery connected.

Can it be a DFU Restore Case? I mean DFU revive didnt work.

Also since all voltages are present when put on charge and a few are missing as soon as the battery is connected the circuit which tells the logic board to turn on and detect the battery is probably having some issue.
 
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Instafixx

Instafixx

Active member
With all connected except trackpad - i get these voltages now and device turns on as well.
Couldn't check the charging as TP/KB not working.

CHGR_PHASE1/2
PPDCIN_AON_CHGR_R
PPVBAT_AON_CHGR_R / PPBUS
CHGR_BGATE
 
2informaticos

2informaticos

Administrator
Staff member
"Couldn't check the charging"
???
Monitoring battery voltage is good enough; it should slowly increase.

Tried known good trackpad board/flex?
 
Instafixx

Instafixx

Active member
Can you help me understand Q5230 and Q5240 because CHGR_PHASE2 and PPDCIN_AON_CHGR_R are not generated when battery is connected.
i dont why i feel the issue is in this section of the board.
 
2informaticos

2informaticos

Administrator
Staff member
Q5230/40 are used depending if charging works in buck, or boost converter mode.
If you can't test correctly, just replace them.
 
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