820-00165 green/orange light, no fan spin. SMC bypass works!

[kevinklinkmuller]

Hi there!

Have 820-00165 green/orange light, no fan spin. SMC bypass works. Was pretty corroded in some places. thought i'd try my luck with the ultra sonic but same issue
So must be a sensor as I understand it?

thanks!

 

[kevinklinkmuller]

I should mention, before it died the customer told me that it would only work with power supply plugged in. Would cut out as soon as it's disconnected.

 

[kevinklinkmuller]

Charger only:

pin 2 = 20v
pin 3 = 5.3v
pin 9 = 0.03
pin 12 = 3.4
pin 13 = 3.3
pin 15 = 0.06
pin 26 = 19.26v

Same result with battery and charger connected

Pin 17/18 3.3 ohms
pins 27/28 20 ohms (seems high?)

3v42 is 3.4v on battery
PPBUS_G3H 7.3v on battery

 

[2informaticos]

Are you using original Apple Magsafe 2 charger?
Input voltage is too high even for 85W charger.
Try a known good one, 60W if possible.

 

[kevinklinkmuller]

Whoops, i was using DCPS. i have a habbit of using this. I'll remeasure it now with the original charger

 

[2informaticos]

Ot lower bench power supply to 16-18V...

 

[kevinklinkmuller]

ok retesting with orignal chargere

pin2 = 16.5
pin 3 = 4.4
pin 9 = 0.03
pin 12 = 3.4
pin 13 = 3.3
pin 15 = 0.06
pin 26 = 16.29

 

[kevinklinkmuller]

same results with battery + charger

 

[2informaticos]

Start checking AVREF_SMC.
Also check all sensors output form page 42.

 

[kevinklinkmuller]

AVREF_SMC is good at 3.3

Nothing at PBUS_S0_VSENSE because there's no SMC_sensor_PWR_EN

DCIN_S5_VSENSE is 2.8V

SMC_CPU_VSENSE 0V

SMC_P1V05S0_VSENSE 0V (I'm guessing all S0 are down for obvious reasons)

SMC_CPUDDR_ISENSE 0V

SMC_P3V3S5_ISENSE 0V




How would it be possible to check sensors that rely on S0 rails if the machine isn't turning on hmmmm

 

[kevinklinkmuller]

I'm probably missing something really simple aren't I

 

[2informaticos]

SMC_DCIN_VSENSE is now OK.
Check SMC_DCIN_ISENSE and SMC_BMON_ISENSE.
No pulse at all at L7520 when SMC_ONOFF_L is triggered?

 

[kevinklinkmuller]

SMC_DCIN_ISENSE is 0.03v
SMC_BMON_ISENSE 0.06v

No pulse with L7520 when SMC_ONOFF_L is triggered

 

[kevinklinkmuller]

I no pulse a good sign or bad sign?

 

[2informaticos]

It should pulse at least, when SMC_ONOFF_L is triggered.
Check first if PM_PWRBTN_L reacts.

"retesting with orignal chargere"
Original Magsafe 2???
You can use bench power supply, with Magsafe 2 cable only.
Never test with Magsafe 1-->2 adapter.

 

[kevinklinkmuller]

How do you know these things yes I'm using an adapter pahahah

changing now and trying it again. I'll check for PM_PWRBTN_L

 

[kevinklinkmuller]

WAIT what the heck

it's working now

 

[kevinklinkmuller]

HOW? I'm now getting 5V at L7520

 

[kevinklinkmuller]

Do you know what happened? do you think this is permanent? or maybe is it just coming on temporary?