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.