820-00165 spins orange light, No backlight Board boot loop after hitting login screen

KuroAkita

New member
To start off, This board and the schematics i aquired seem to be different. Some bits on the schematic appear to be missing compared to all of the 820-00165 boards i have.

I am measuring dcin and only getting 18v instead of 25v The backlight connector does not get above 8v.
Not sure where to go from here. Have tried multiple dc in boards and connectors.
We also do not get power unless both the battery and charger are plugged in.
 

2informaticos

Administrator
Staff member
"I am measuring dcin and only getting 18v instead of 25v"
Where exactly and why assume 25V???

I recommend you solve the power problem before go ahead.
Exact value for PPBUS_G3H with charger and w/ and w/o battery?
Check resistance between pins 17/18 and 27/28 of ISL6259.
 

KuroAkita

New member
PPBUS_G3H with battery reads 8.55v
PPBUS_G3H without battery reads 8.56v
Resistance Between pin 17/18 is 3.2 and pin 27/28 is reading 20.5
 

2informaticos

Administrator
Staff member
Seems to have a problem with battery bus.
Check resistance to ground (diode mode) for SCL/SDA lines of that bus.
 

KuroAkita

New member
SCL is giving 11.23kohm pin4
SDA is giving 46.5 kohm pin5

This is with red on left usb for ground black on pins.
 

KuroAkita

New member
My mistake other way around. SCL is 46.5
SDA us 11.23
EDIT: the readings seem to keep flipping. keeping red on earth all the time..
 
Last edited:

2informaticos

Administrator
Staff member
You can't get "kohm" mark on diode mode...
Less than 1% difference is required there.
Even ohm scale, gave you bigger difference.
Don't forget to check voltage too.
 

KuroAkita

New member
Ok I believe I have the right setting.
i am using a fluke 15b+.
I rotated the selection to the ohm symbol and pressed the yellow button twice. I now have a diode symbol in the top right .presumably this is what you meant.

SCL reads 0.504v
sca reads 0.502v
 

2informaticos

Administrator
Staff member
The values are pretty equal.
But you should also get similar difference on ohm scale...
Post voltage for both lines too.
Does the board start on charger only (no battery)?
 

KuroAkita

New member
smc bypass boots.. doesnt seem to be turning of altough fans are running extremely loud.. could this mean dead smc?
 

2informaticos

Administrator
Staff member
Fan spins at max in SMC bypass mode, that is normal behaviour.
You have some sensor which blocks SMC to start.
Check the sensors output from page 42.
Start with SMC_DCIN_VSENSE and SMC_PBUS_VSENSE.
 

KuroAkita

New member
smc dcin vsense is 18v
smc pbus vsense is 8.5v
smc cpu isense is 0.122v
we have no u5570
we have no u5560
we have no u5590
cpuvr adjust isense is 0.003
no u5670
any more we need?
 
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