OLD 820-2978 No PM_SLP_S4_L

Bouba148

New member
water damage around U6500

PPBUS 12.57V but going down after 3-5 sec
PP3V42 : OK but NO green light

Reflowed U7200 now PPBUS OK: 12.57V and green light came then went after unpluggled the charger
S5 Rails OK
S3 Rails NOK when shorting power pads (R5015)
No PM_SLP_S4_L

PM_BATLOW_L: 0V
SMC_RESET_L: 3.414V
SMC_PM_G2_EN: 3.411V

Board turning ON in SMC bypass mode
 

2informaticos

Administrator
Staff member
Check SMC_PBUS_VSENSE, SMC_DCIN_ISENSE and SMC_BATT_ISENSE values.
Also try another charger.
Does it charge the battery?
Turns on with battery only?

Post exact resistance between pins 17/18 and 27/28 of U7000.

Isn't 2879 board?
 

Bouba148

New member
It is 2879 board

Already checked R17/18: 3 Ohms R27/28: 20 Ohms
With Official Apple 85W charger the green light turns ON but still the board doesn't turn ON
When the battery plugged Green light stays green doesn't turn Orange.
Turns ON with the battery but fan ramps up to full speed: CPU getting Hot

SMC talking to battery as I can see activity on SDA and SCL bus
Once the board turns ON with the battery and plugged the charger, disconnected the battery: it stays ON with the charger only connected

SMC_PBUS_VSENSE: 1.873V with both battery and charger: 2.104V
SMC_DCIN_ISENSE : 0V with only battery, with both battery and charger: 0.38V then 0.422V when Fan at Full Speed
SMC_BATT_ISENSE: 0.598V with both battery and charger: 0.6V
 
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2informaticos

Administrator
Staff member
"SMC_BATT_ISENSE: 0.598V with both battery and charger: 0.6V"
Too high.
Post CHGR_AMON/BMON voltage.
Specify values for charger only, no battery.
 

Bouba148

New member
Hi 2Informaticos,

I'm surprised to notice that there no U5413 on that 820-2879 Board........interesting no?.................hummmmm!
I should maybe work with some other board schematic or think about U7000?

Click image for larger version  Name:	Model Number.jpg Views:	0 Size:	15.9 KB ID:	50661Click image for larger version  Name:	U5413.jpg Views:	0 Size:	61.8 KB ID:	50663
 

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2informaticos

Administrator
Staff member
Then R5431 is soldered.

"Already checked R17/18: 3 Ohms"
Did you check directly between pins?

"CHGR_BMON: 0.068V with charger only"
"SMC_BATT_ISENSE: 0.598V with both battery and charger: 0.6V"
Please confirm values.
High CHGR_BMON can block SMC.
This will explain starting on SMC bypass...
 

Bouba148

New member
I came back to that board and noticed that I've lost the ppbus with the charger (0.7V) so I decided to check with the battery only: the U7000 fried!
Replaced,checked R17/18 and R27/28 before putting back under power: R17/18 too high: 174Ohms checked my soldering job around ISL, found out R7051 too high, replaced it.
Then PPBUS 12.67V with official 85W charger but slowly dropping down then pulsing in loop.
Reflowed U7200.
Now PPBUS 12.67V solid and stable.
Machine turning ON with charger only in SMC bypass mode or with battery.

with charger only (board not turning ON ):CHGR_BMON : 0.07V
with charger only in SMC bypass mode CHGR_BMON: 0.069V
with the battery only, board OFF: CHGR_BMON: 0.07V
with the battery board ON: around 0.600V

Exact same values in same configuration for SMC_BATT_ISENSE
 

Bouba148

New member
I'm mesuring 2.9Ohms directly on pins 17/18 of the ISL, if you remove around 1 Ohm of the fluke probes it's OK.

Triple Checked the soldering there shoud be OK , what do you think?

ISL R17_18.jpg
 

2informaticos

Administrator
Staff member
Looks good...

If board always starts in SMC bypass mode, should be an I/VSENSE sensor issue.
Do you get AVREF_SMC?
 

Bouba148

New member
yes

PP3V3_S5_AVREF_SMC: 3.299V

You wrote: "If board always starts in SMC bypass mode, should be an I/VSENSE sensor issue."

So I'll check all the I/V sense signals at page 39 , 43 , 44, 51 etc....
In the mean time I've noticed that it is not charging the battery as it's pulling only 30 mA, which could make sense as for security: I/V sense issue ---> STOP CHARGING Am I right?
 
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Bouba148

New member
On Charger:

OFF SMC BYPASS:
SMC_CPU_ISENSE: 0V 0.380V
SMC_CPU_VSENSE: 0V 1.162V
SMC_DCIN_ISENSE: 0.039V 0.454V
SMC_PBUS_VSENSE: 0V 2.073V
SMC_BATT_ISENSE: 0.069V 0.068V
SMC_NB_MISC_ISENSE: 0V 2.495V ?
SMC_MCP_VSENSE: 0V 1.225V
SMC_CPU_FSB_ISENSE: 0.610V 0.738V
SMC_MCP_CORE_ISENSE: 0V 0.610V
SMC_MCP_DDR_ISENSE: 0V 0.303V

On Battery:

OFF: ON:
SMC_CPU_ISENSE: 0V 0.370V
SMC_CPU_VSENSE: 0V 1.162V
SMC_DCIN_ISENSE: 0V 0.454V
SMC_PBUS_VSENSE: 0V 1.727V
SMC_BATT_ISENSE: 0V 0.658V
SMC_NB_MISC_ISENSE: 0V 2.495V ?
SMC_MCP_VSENSE: 0V 0.950V
SMC_CPU_FSB_ISENSE: 0.599V 0.540V
SMC_MCP_CORE_ISENSE: 0V 0.322V
SMC_MCP_DDR_ISENSE: 0V 0.008V
 
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Bouba148

New member
On Charger:

SMC_CPU_ISENSE: 0V
SMC_CPU_VSENSE: 0V
SMC_DCIN_ISENSE: 0.039V
SMC_PBUS_VSENSE: 0V
SMC_BATT_ISENSE: 0.069V
SMC_NB_MISC_ISENSE: 0V
SMC_MCP_VSENSE: 0V
SMC_CPU_FSB_ISENSE: 0.610V
SMC_MCP_CORE_ISENSE: 0V
SMC_MCP_DDR_ISENSE: 0V

SMC BYPASS:
SMC_CPU_ISENSE: 0.380V
SMC_CPU_VSENSE: 1.162V
SMC_DCIN_ISENSE: 0.454V
SMC_PBUS_VSENSE: 2.073V
SMC_BATT_ISENSE: 0.068V
SMC_NB_MISC_ISENSE: 2.495V
SMC_MCP_VSENSE: 1.225V
SMC_CPU_FSB_ISENSE: 0.738V
SMC_MCP_CORE_ISENSE: 0.610V
SMC_MCP_DDR_ISENSE: 0.303V

On Battery

OFF:
SMC_CPU_ISENSE: 0V
SMC_CPU_VSENSE: 0V
SMC_DCIN_ISENSE: 0V
SMC_PBUS_VSENSE: 0V
SMC_BATT_ISENSE: 0V
SMC_NB_MISC_ISENSE: 0V
SMC_MCP_VSENSE: 0V
SMC_CPU_FSB_ISENSE: 0.599V
SMC_MCP_CORE_ISENSE: 0V
SMC_MCP_DDR_ISENSE: 0V

ON:
SMC_CPU_ISENSE: 0.370V
SMC_CPU_VSENSE: 1.162V
SMC_DCIN_ISENSE: 0.454V
SMC_PBUS_VSENSE: 1.727V
SMC_BATT_ISENSE: 0.658V
SMC_NB_MISC_ISENSE: 2.495V
SMC_MCP_VSENSE: 0.950V
SMC_CPU_FSB_ISENSE: 0.540V
SMC_MCP_CORE_ISENSE: 0.322V
SMC_MCP_DDR_ISENSE: 0.008V
 
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Bouba148

New member
removed R2598, and tryied to start the board in normal mode: NOK
On the board the pin1 ( SMC_N_FOLLOW ) is still 2.5V but as removed R2598: 0V on pin 2.

Something is still preventing the SMC to turn ON the board:
I will double check SMC_PBUS_VSENSE and SMC_CPU_VSENSE as they're higher that the other rails.....
 

Bouba148

New member
Removed R5385 for SMC_PBUS_VSENSE: NOK
with R5385 still removed I've also removed R5309 for SMC_CPU_VSENSE still :NOK

Next step will be to remove all the resistors that bringing all the I and V sense rails to the SMC, if still not OK so in that case I would suspect the SMC.......
What do you think?
 
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