sangolossyfon
Member
Board symptoms- No sign of life at all. No shorts on any 5V-3V3 S5, S3, S0 rails. No fan spin even when attempted SMC bypass. G3H voltage 13.23V. Draws about 1 watt from wall in regular or SMC bypass mode.
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820-3115-B No Power
- Thread starter sangolossyfon
- Start date
What about 3V42_G3H?
sangolossyfon
Member
it is 3.8v
Post U5010 voltages.
sangolossyfon
Member
U5010
1 PP3V42_G3H- 3.8
2 GND_SMC_AVSS- 0
3 PP3V42_G3H- 3.8
4 SMC_MANUAL_RST_L- 4.3
5 SMC_RESET_L- 3.5
6 SMC_TPAD_RST_L- 3.7
7 SMC_ONOFF_L- 3.7
8 PP3V3_S5_AVREF_SMC- 3.5
1 PP3V42_G3H- 3.8
2 GND_SMC_AVSS- 0
3 PP3V42_G3H- 3.8
4 SMC_MANUAL_RST_L- 4.3
5 SMC_RESET_L- 3.5
6 SMC_TPAD_RST_L- 3.7
7 SMC_ONOFF_L- 3.7
8 PP3V3_S5_AVREF_SMC- 3.5
Post U7200 basic voltages: pins 16, 3, 8, 17, 1, 6.
sangolossyfon
Member
in the process of measuring voltages I realized that u7200 gets very hot and board now draws 3w and doesn't have green light. I might have tapped two pins together to cause this but I will replace U7200 and update after.
edit: replaced u7200. board not booting same as before but u7200 not getting hot anymore so I assume my touching two pins shorted u7200. green light is back.
Voltages on new u7200-
16- 13.4v
3- 4.2v
8- 0.03v
17- 13.4v
1- 0.01v
6- 3.7v
edit: replaced u7200. board not booting same as before but u7200 not getting hot anymore so I assume my touching two pins shorted u7200. green light is back.
Voltages on new u7200-
16- 13.4v
3- 4.2v
8- 0.03v
17- 13.4v
1- 0.01v
6- 3.7v
"17- 13.4v"
I really doubt about this.
Be sure do not touch pins 16/17 at same time!
Check diode mode to ground at pin 8.
I really doubt about this.
Be sure do not touch pins 16/17 at same time!
Check diode mode to ground at pin 8.
sangolossyfon
Member
diode mode reads 920 to ground pin 8
but yes measuring the resistor right next to chip that is connected to 17 on boardview yields 13.4v
but yes measuring the resistor right next to chip that is connected to 17 on boardview yields 13.4v
I don't see any resistor connected to pin 17; there is only one capacitor (C7273).
It MUST have 5V; if not, replace U7200.
It MUST have 5V; if not, replace U7200.
sangolossyfon
Member
I actually was measuring the voltages of U7000 not U7200. Sorry for wasting your time on that. Here are the correct voltages.
The chip next to it, Q7221, was also not getting any voltage on any pins.
Posted below are working, powered-on board voltages and dead board voltages on the right. so the difference is pin 1.
1- 1.26, 0v
3- 2.13, 2.2v
6- 0.87, 0.84v
8- 3.66, 3.65v
16- 13.8, 13.86v
17- 5.61, 5,52v
The chip next to it, Q7221, was also not getting any voltage on any pins.
Posted below are working, powered-on board voltages and dead board voltages on the right. so the difference is pin 1.
1- 1.26, 0v
3- 2.13, 2.2v
6- 0.87, 0.84v
8- 3.66, 3.65v
16- 13.8, 13.86v
17- 5.61, 5,52v
With these values, you should have 3.3V at C7251.
sangolossyfon
Member
yes there is 3.88v
Do you get 3V3_SUS_FET voltage?
If not, check PM_SLP_SUS_L.
If not, check PM_SLP_SUS_L.
sangolossyfon
Member
yes 3.79v
Trigger SMC_ONOFF_L and check for drop pulse at PM_SLP_S4_L (at same time).
sangolossyfon
Member
I do not have a scope, but there is no voltage on this rail no matter what I do. Tried measuring while I plug in board and also when I subsequently connect poweron pads and in SMC bypass mode.
Also it seems like SMC bypass mode isn't even registered. Even when poweron pads are connected while charger is connected, there is still a green light and the board draws 1 watt immediately. Normally in SMC bypass mode the green light stays off while the button is held and the board doesn't draw power until the fans turn on.
Also it seems like SMC bypass mode isn't even registered. Even when poweron pads are connected while charger is connected, there is still a green light and the board draws 1 watt immediately. Normally in SMC bypass mode the green light stays off while the button is held and the board doesn't draw power until the fans turn on.
Be sure SMC_ONOFF_L stays high (3V).
When you trigger it (temparary shorting to ground), check for drop pulse at PM_PWRBTN_L (at same time).
No need to use oscilloscope.
Use R5015/16 pads, instead of power button.
When you trigger it (temparary shorting to ground), check for drop pulse at PM_PWRBTN_L (at same time).
No need to use oscilloscope.
Use R5015/16 pads, instead of power button.
sangolossyfon
Member
yes I have been using the pads
yes SMC_ONOFF_L stays high while board is connected to power
PM_PWRBTN_L also stays at 3.5v when board is connected to power
when I short SMC_ONOFF_L to ground, PM_PWRBTN_L goes down to 0.3v
yes SMC_ONOFF_L stays high while board is connected to power
PM_PWRBTN_L also stays at 3.5v when board is connected to power
when I short SMC_ONOFF_L to ground, PM_PWRBTN_L goes down to 0.3v
In such case, PM_SLP_S4_L should pulse high, at same time.
If not, check PM_RSMRST_L level; it must stay always high.
If not, check PM_RSMRST_L level; it must stay always high.