MacBook A1342 820-2567: green light but won't turn on

[DrFalken]

Hello everybody !
I've a MacBook A1342, M/B 820-2567, that won't turn on.
Magsafe is solid green, when I press power button the fan spin for just half second.

Some readings:
PPBUS_G3H = 12,58V
PP3V3_S5 = 3,3V
PP3V42_G3H = 3,42V
PP1V1R1V05_S5 = 1,05V
PP18V5_G3H = 16,95V

[natic]

Re: MacBook A1342 820-2567: green light but won't turn on

Hello!

Measure the resistances to ground on all coils. Measure with the power supply and battery disconnected from the board.

[DrFalken]

Re: MacBook A1342 820-2567: green light but won't turn on

Hello!

Measure the resistances to ground on all coils. Measure with the power supply and battery disconnected from the board.

L9710 > 2 MOhm
L7620 = 115 Ohm
L7400 = 17 Ohm
L7401 = 17 Ohm
L7320 = 160 Ohm
L7000 > 2 MOhm
L7260 > 10 kOhm
L7220 > 15 kOhm

Schematic and boardview ---> https://www.badcaps.net/forum/showth...54#post1265954

[Vesko356]

Re: MacBook A1342 820-2567: green light but won't turn on

L9710 > 2 MOhm...

Do not attach schematics/boardviews in this section please!

Schematic Requests ONLY!
https://www.badcaps.net/forum/forumdisplay.php?f=41

Reminder: rules and organization of this section
https://www.badcaps.net/forum/showthread.php?t=117483

If you request/offer BIOS/schematics/boardviews, please post in the appropriate subsection, and you can link to it in the troubleshooting topic.

.

[DrFalken]

Re: MacBook A1342 820-2567: green light but won't turn on

I'm taking some voltages: found missing P5V3V3_PGOOD

[DrFalken]

Re: MacBook A1342 820-2567: green light but won't turn on

Readings I've done so far:
U6900
- Pin 1 (SMC_BC_ACOK_VCC) = 3,4
- Pin 2 (GND) = GND
- Pin 3 (-) = -
- Pin 4 (SYS_ONEWIRE) = 3,38
- Pin 5 (ADAPTER_SENSE_R) = 3,38

Q7001
- Pin 1+2+3 (PPVDCIN_G3H_PRE) = 16,44
- Pin 4 (CHGR_LOWCURRENT_GATE_R) = 15,33
- Pin 5 (PPVDCIN_G3H_PRE2) = 16,95

Q7000
- Pin 1+2+3 (PP18V5_G3H) = 16,95
- Pin 4 (CHGR_SGATE) = 6,23
- Pin 5 (PPVDCIN_G3H_PRE2) = 16,95

Q7220
- Pin 1 (3V3S5_DRVH) = 3,34
- Pin 2 (PPBUS_G3H) = 12,57
- Pin 3 (GND) = GND
- Pin 4 (GND) = GND
- Pin 5 (GND) = GND
- Pin 6 (3V3S5_DRVL) = 0,15
- Pin 7 (3V3S5_LL) = 3,28

U7200
- Pin 1 (5V_S3_ENTRIP) = 0
- Pin 2 (5V_S3_VFB) = 0
- Pin 3 (5VS3_3V3S5_VREF) = 1,98
- Pin 4 (5V3V3S5_REG3) = 3,3
- Pin 5 (3V3S5_VFB) = 2,02
- Pin 6 (3V3S5_ENTRIP) = 0,71
- Pin 7 (3V3S5V02VO2) = 3,3
- Pin 8 (5V3V3S5_REG3) = 3,3
- Pin 9 (3V3S5_VBST) = 7,62
- Pin 10 (3V3S5_DRVH) = 3,34
- Pin 11 (3V3S5_LL) = 3,28
- Pin 12 (3V3S5_DRVL) = 1,98
- Pin 13 (5V3V3_REG_EN) = 3,2
- Pin 14 (5VS3_3V3S5_VREF) = 1,98
- Pin 15 (GND) = GND
- Pin 16 (PPBUS_G3H) = 12,58
- Pin 17 (5V3V3S5_REG5) = 4,95
- Pin 18 (-) = -
- Pin 19 (5V_S3_DRVL) = 0
- Pin 20 (5V_S3_LL) = 0
- Pin 21 (5V_S3_DRVH) = 0
- Pin 22 (5V_S3_VBST) = 4,43
- Pin 23 (P5V3V3_PGOOD) = 0
- Pin 24 (5V_S3_VO1) = 0
- Pin 25 (GND) = GND


P1V05_S5_PGOOD = 3,09
CPUVTTS0_PGOOD = 0
DDRREG_PGOOD = 0,09
MCPCORES0_PGOOD = 0
P1V05S0_LDO_PGOOD = 0
P1V05S0_PGOOD = 0
P5V3V3_PGOOD = 0
ALL_SYS_PWRGD = 0
S0_AND_IMVP_PGOOD = 0
S0PGOOD_PWROK = 0
VR_PWRGOOD_DELAY = 0,02
CPU_PWRGD = 0
MCP_PS_PWRGD = 0
RSMRST_PWRGD = 3,09
XDP_PWRGD = 0
PM_SLP_S4_L = 0
PM_SLP_S3_L = 0
PPVIN_S5_IMVP6_VIN = 12,57
PPBUS_G3H_CPU_ISNS = 12,57

[DrFalken]

Re: MacBook A1342 820-2567: green light but won't turn on

Just a reading fix:
- Pin 12 (3V3S5_DRVL) = 0.15V

Now I'll check the BIOS...

Update:
I've flashed the BIOS chip (rom file found on Alisaler, same A1342 820-2567 board) & verified the flash.
Now the laptop turn on, fan at full speed but black screen.
I'm trying SMC & PRAM reset...but doesn't seem to make difference.

[DrFalken]

Re: MacBook A1342 820-2567: green light but won't turn on

I've just noticed that the board P/N is 820-2567-A (not just 820-2567) so I've tried flashing bios from https://www.badcaps.net/forum/showpo...9&postcount=10 and now the laptop doesn't turn on again (fan spin for just half second)

[natic]

Re: MacBook A1342 820-2567: green light but won't turn on

I've tried flashing bios from https://www.badcaps.net/forum/showpo...9&postcount=10 and now the laptop doesn't turn on again (fan spin for just half second)

Please, reflash the BIOS chip again back with your old (backup) BIOS dump.

Then measure the voltages to ground on all coils for a short time right after pressing to the power button. You will need to turn on the machine multiple times to measure all of the voltages.

[DrFalken]

Re: MacBook A1342 820-2567: green light but won't turn on

Please, reflash the BIOS chip again back with your old (backup) BIOS dump.

Then measure the voltages to ground on all coils for a short time right after pressing to the power button. You will need to turn on the machine multiple times to measure all of the voltages.

Sorry for the late reply

L9710 = 0
L7620 >1,0
L7400 >1,0
L7401 >1,0
L7320 >1,5
L7000 = 12,64
L7260 >5,0
L7220 = 3,328

bold readings are always present, the others last less that .5 second.