MacBook A1278 main 820-2530b not charge, it turns on only with battery

[reset1986]

hi, I have this macbook that works correctly with battery inserted, if I connect the power supply the light turns green but it does not charge, if I disconnect the battery and connect only the power supply the light turns green and the mac enters the ignition loop 4/5 sec, turns off and repeats itself,

on the motherboard there are no traces of liquid or damaged components,

I tested the 3.42 and they are constant both with power supply and with battery,
advice on what signs I can start checking?
the power supply indicator light never turns orange,
power supply working on other macs
thanks a lot

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

hi.

1) with the battery only - is the logic board able to report the battery status (value) ? If yes, then the SMBUS_I2C lines on the battery are working. Check for this.

2) Try to do the PRAM reset to see if this fixes the issue.

3) If the status of the battery is not being reported, then check & post the voltage readings on:

a) SMBUS_BATT_SCL
b) SMBUS_BATT_SDA

4) Otherwise, study the power boot sequence showing on sheet # 3 / 81.

The number inside each circle is the power on order that must be met to allow for the logic board to boot and operate normally.

5) U7000 page should be studied which is the main charger and DC adapter power rail IC. It is possible that some component (mosfet?) is shorted. More on this after the above feedback is posted.

[reset1986]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

hi.

1) with the battery only - is the logic board able to report the battery status (value) ? If yes, then the SMBUS_I2C lines on the battery are working. Check for this.

2) Try to do the PRAM reset to see if this fixes the issue.

3) If the status of the battery is not being reported, then check & post the voltage readings on:

a) SMBUS_BATT_SCL
b) SMBUS_BATT_SDA

4) Otherwise, study the power boot sequence showing on sheet # 3 / 81.

The number inside each circle is the power on order that must be met to allow for the logic board to boot and operate normally.

5) U7000 page should be studied which is the main charger and DC adapter power rail IC. It is possible that some component (mosfet?) is shorted. More on this after the above feedback is posted.

thanks, yes the battery percentage is managed and correct,
Seeing the ignition sequence and with the battery inserted you go to bypass U7000,
I check that air and post the results, thanks

[reset1986]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

hi.

1) with the battery only - is the logic board able to report the battery status (value) ? If yes, then the SMBUS_I2C lines on the battery are working. Check for this.

2) Try to do the PRAM reset to see if this fixes the issue.

3) If the status of the battery is not being reported, then check & post the voltage readings on:

a) SMBUS_BATT_SCL
b) SMBUS_BATT_SDA

4) Otherwise, study the power boot sequence showing on sheet # 3 / 81.

The number inside each circle is the power on order that must be met to allow for the logic board to boot and operate normally.

5) U7000 page should be studied which is the main charger and DC adapter power rail IC. It is possible that some component (mosfet?) is shorted. More on this after the above feedback is posted.

hi, I found Q7030 pin 123 CHGR_PHASE and pin 4 CHGR_UGATE measured in diode mode low value 10ohm

q7030 tested looks ok, replaced U7000 ISL6258a,
the value is back to high, given power to the motherboard with power supply, switching on and off in repetition,
measured again CHGR_PHASE and CHGR_UGATE again low value 10/12 ohm,
there are no short

do you have any advice? thanks a lot

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Review this webpage:

https://www.badcaps.net/forum/showthread.php?t=90356

Post the voltages on each pin of U7000 with the adapter and battery connected.

Post voltages of U7000 without adapter but battery connected.

[reset1986]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Review this webpage:

https://www.badcaps.net/forum/showthread.php?t=90356

Post the voltages on each pin of U7000 with the adapter and battery connected.

Post voltages of U7000 without adapter but battery connected.

ok just measured

with battery inserted and mac turned off
1 0V
2 0V
3 0V
4 3.44V
5 0V
6 3.44
7 0
8 0
9 0
10 3.42
11 3.42
12 3.44
13 3.42
14 0
15 0.05
16 3.75
17 10.66
18 10.66
19 0
20 0
21 0
22 GND
23 10.66
24 10.66
25 10.34
26 14
27 13.90
28 13.80
29 GND

with battery inserted and power supply, mac off with green led
1 0V
2 16.45
3 3.92
4 3.44V
5 0.18
6 3.44
7 0.72
8 1.76
9 0.03
10 3.42
11 3.42
12 3.44
13 3.42
14 3.30
15 0.05
16 3.22
17 10.65
18 10.65
19 5.06
20 5.06
21 0
22 GND
23 10.66
24 10.58
25 10.13
26 16.05
27 16.30
28 16.30
29 GND

thanks

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

1) What is the voltage of PPBUS_G3H with the adapter & battery ?

2) What is the voltage of PPBUS_G3H with the adapter (only) & no battery ?

3) Power down, remove adapter & battery.

Meter in resistance mode.

Post the resistance for the following:

a) source (1-2-3) & drain (5-6-7-8) of Q7050

b) source (1-2-3) & gate (4) of Q7050

c) gate (4) & drain (5-6-7-8) of Q7050

4) Are you using an original magsafe 85W power supply ? With the battery out, does the magsafe LED turn orange (amber) ?

5) Can you test with another known good battery ?

6) Place meter in diode mode and post the diode readings for the SCL / SDA lines for the battery interface.

a) Red meter lead to ground. Black meter lead on SMBUS_BATT_SCL. Diode reading ?

b) Red meter lead to ground. Black meter lead on SMBUS_BATT_SDA. Diode reading ?

[reset1986]

Re: MacBook A1278 main 820-2936b not charge, it turns on only with battery

1) What is the voltage of PPBUS_G3H with the adapter & battery ?

2) What is the voltage of PPBUS_G3H with the adapter (only) & no battery ?

3) Power down, remove adapter & battery.

Meter in resistance mode.

Post the resistance for the following:

a) source (1-2-3) & drain (5-6-7-8) of Q7050

b) source (1-2-3) & gate (4) of Q7050

c) gate (4) & drain (5-6-7-8) of Q7050

4) Are you using an original magsafe 85W power supply ? With the battery out, does the magsafe LED turn orange (amber) ?

5) Can you test with another known good battery ?

6) Place meter in diode mode and post the diode readings for the SCL / SDA lines for the battery interface.

a) Red meter lead to ground. Black meter lead on SMBUS_BATT_SCL. Diode reading ?

b) Red meter lead to ground. Black meter lead on SMBUS_BATT_SDA. Diode reading ?

PPBUS_G3H with power supply and battery 10.60

PPBUS_G3H with power supply and without battery, goes into power on off, I measure 12.50V, then turns off I measure 3.5V
PPBUS_G3H measured on F7040


q7050 should be the q7055 on this main 820-2936b, my mistake, I correct the title , place schematic and brd
q7055 measurements
a) 123--5678 113Kohm, inverting the wires to infinity
b) 123--4 1.4 Mohm by inverting the leads infinity
c) 4 --- 5678 I have no 2K-200K-2M scale readings

original power supply working on another 1278, new battery charged to 40%

SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA
measured in diode mode, 223 both

thanks for your help

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

1) What chip was soldered in @ U7000 ? It has to be the ISL6259.

2) Desolder D6950 and remove all power (no adapter / no battery) and check the diode readings again on the battery SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA lines.

Post the results.

[piernov]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

L2008-M2009 MacBooks use ISL6258 not ISL6259.

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

L2008-M2009 MacBooks use ISL6258 not ISL6259.

OMG. The 820-2530 uses ISL6258 @ U7000 ?

The 820-2530 schematic shows as ISL6259.

Noting this correction, to the OP, which part do you have @ U7000 ?

[reset1986]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

L2008-M2009 MacBooks use ISL6258 not ISL6259.

OMG. The 820-2530 uses ISL6258 @ U7000 ?

The 820-2530 schematic shows as ISL6259.

Noting this correction, to the OP, which part do you have @ U7000 ?

here I am, U7000 isl6259A,
I made a mistake in the title
the motherboard is 820-2936b, I posted the schematic, soon I will post measurements of SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA lines. without diode

thanks a lot

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Ok. 820-2936b from schematics and Louis' forum notes U7000 as ISL6259. Be sure that it is soldered properly - 'make it dance' with the flux and hot air.

[reset1986]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Ok. 820-2936b from schematics and Louis' forum notes U7000 as ISL6259. Be sure that it is soldered properly - 'make it dance' with the flux and hot air.

desoldered D6950
SMBUS_SMC_BSA_SCL and SMBUS_SMC_BSA_SDA 223 measured in diode mode, 223 both as when d6950 is soldered

but the q7030 123--4 10 Ohm is normal?

isl6259 welded correctly

thanks

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

but the q7030 123--4 10 Ohm is normal?

Sounds low to me. Desolder it and check the resistance again on this mosfet when it is out of circuit.

Source - drain ?

Source - gate ?

gate - drain ?

Likely it needs to be replaced.

The diode values may be ok on the I2C lines but internet (Louis' forum) - states it should be about 0.4 - 0.45. For now, do not worry about these values.

The mosfet @ Q7030 is of concern.

See the tables here for guidance.

http://electronicsbeliever.com/how-t...-is-defective/

[reset1986]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Sounds low to me. Desolder it and check the resistance again on this mosfet when it is out of circuit.

Source - drain ?

Source - gate ?

gate - drain ?

Likely it needs to be replaced.

The diode values may be ok on the I2C lines but internet (Louis' forum) - states it should be about 0.4 - 0.45. For now, do not worry about these values.

The mosfet @ Q7030 is of concern.

See the tables here for guidance.

http://electronicsbeliever.com/how-t...-is-defective/

ok, unsoldered q7030, q7035, q7055

test with 200K scale
q7030, q7035 q7055
123 --- 5678 110K
tapping pin 4
123 --- 5678 76K

123 --- 4 0 Kohm
4 ---- 5678 0 Kohm

inverting the tips I have no measures, they seem ok

q7030 on the motherboard I still have 10 ohms between 123--4
desoldering U7000 the value increases,
i had tried to replace U7000 the value before power on was correct between 123--4 of q7030, then it decreased again

[lazaro.089]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Hi! I have the same exact problem than you!
Low resistance between Ugate and phase of U7000. (Like 4 to 10 ohms)
Also "Looping" every 5 seconds in PPBUS_G3H with charger only.

With battery works fine. Already replaced Q7030 and U7000 with brand new chips. Same problem

This is PPBUS_G3H readings.
I'm suspecting SMC but I want to discard everything before changing it.

[lazaro.089]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Ok, I think I'm getting closer.

Please, take a reading at U7000 pin 26.

Mine is around 18v. It should be 0 so Q7080 saturates through the voltage divider.

I have changed U7000 several times. My thoughts are that the SMC isn't communicating to ISL through SMBUS_SMC_BSA_SCL & SMBUS_SMC_BSA_SDA correctly.

I'll try and check the comunication.

[mon2]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

U7000 is a delicate device. If you have not done so already, use lots of flux and dial up high heat with good air pressure.

For our tool, 500C and 50-65 percent on the air around the ic. Then we wait till the chip dances around the pcb pads where it lives. Just be careful to not disturb nearby parts. Then we are confident the balls have aligned ok.

Just did the same recently for an ipad TriStar repair.

[lazaro.089]

Re: MacBook A1278 main 820-2530b not charge, it turns on only with battery

Thanks mon2 I'll try it again. Maybe is wrongly soldered.
@reset86, any news?