a1278 board 820-2936-b doesn't charge

[opethfan]

hi
I have a macbook pro that doesn't charge (820-2936-b)
this is my situation:

- magsafe has always green led, the macbook works well with it plugged.

- if i connect an already charged battery it won't turn on but

- after power on with magsafe, it stays on when i disconnect it (with charged battery)

i haven't any service manual...

please help me... thanks

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

UPDATE:

there is a short circuit, please see picture

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

someone has birdview please?

[kotnatan]

Re: a1278 board 820-2936-b doesn't charge

820-2936_APPLE Macbook A1278 (FLYING_CLOUD,MLB,K90i EVT3)_051-8658 - BoardView
http://**************/load/noutbuki/apple/820_2936_apple_macbook_a1278_flying_cloud_mlb_k90i_evt3i_051_8658_boardview/311-1-0-24882

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

the site is in russian language and i can't pass their entry test.

[atsio]

Re: a1278 board 820-2936-b doesn't charge

Try this

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

SMBUS_SMC_BSA_SDA is short circuit... 0 volts
where can be the problem with it?

[dellxps15]

Re: a1278 board 820-2936-b doesn't charge

correct schematic.

check pin 10 of u7000 "SMBUS_SMC_BSA_SDA" if shorted.
remove "BIL" cable and check again.

if still short remove u7000 and check if still shorted pin 10 u7000.

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

pin 10 was shorted, removed u7000 the short was gone so i replaced u7000 (from another board) and now same short on pin 10

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

the short is made now from the bil cable, but if i disconnect it the led is same green and there is always the x on the battery icon

[dellxps15]

Re: a1278 board 820-2936-b doesn't charge

remove c6952 and check again.

if still short remove d6950 and check again.
edit: check also r6950 value if it's 10k.

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

the short is linked to the bil cable... i have ordered a new one.
but the led is still green

[dellxps15]

Re: a1278 board 820-2936-b doesn't charge

voltage on battery pin ?
r6950 ?

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

voltage on r6950 is 0v

pin 4 3.5 v
pin 5 0v
pin 6 3.5v
pin 7 12v
pin 8 12v
pin 9 12v

measures taken with battery connected

[dellxps15]

Re: a1278 board 820-2936-b doesn't charge

how many ohm ? and 0volt both side ?

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

10 k ohm and 0v on both sides

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

who know where sys_detect-l voltage come from?

[opethfan]

Re: a1278 board 820-2936-b doesn't charge

the magsafe has always green led... sys_detect-l is 0 volts... someone can help me please?

[MobileXT]

Re: a1278 board 820-2936-b doesn't charge

the magsafe has always green led... sys_detect-l is 0 volts... someone can help me please?

Check the all current sensing resistor at U7000 chips

[angel-boy]

Re: a1278 board 820-2936-b doesn't charge

i have a 820-2936-b board that not charging the battery and appers not available , i change ISL with second used one , nothing change. any help ?