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820-00840 Not powering on after UC
- Thread starter tlough75
- Start date
Why the people like so much to pass a board through UC?
To clean few caps, use toothbrush!
Now you can have knocked off components, or broken traces.
Did you use sweep function at least?
Did you dry the board correctly?
Do you get 3V3_S5/SUS at least?
To clean few caps, use toothbrush!
Now you can have knocked off components, or broken traces.
Did you use sweep function at least?
Did you dry the board correctly?
Do you get 3V3_S5/SUS at least?
I've got ONE reply for 3 questions; what should I understand???
tlough75
Member
you actually asked 4 questions.
Answer 1. Because there was flux that may have gone under U7800 because the cap I replaced was right above it.
Answer 2. Yes I used the sweep function
Answer 3. I dried for 1 hour
Answer 4. I was getting PP3V3_S5. When I search for SUS I don’t see anything for that.
Answer 1. Because there was flux that may have gone under U7800 because the cap I replaced was right above it.
Answer 2. Yes I used the sweep function
Answer 3. I dried for 1 hour
Answer 4. I was getting PP3V3_S5. When I search for SUS I don’t see anything for that.
You cannot get S4 voltages, nor signals, if missing 3V3_SUS.
This imply missing PM_SLP_SUS_L and you have to find why PCH pulls down that signal.
Start checking PCH's RTC signals and U7800 at page 60.
This imply missing PM_SLP_SUS_L and you have to find why PCH pulls down that signal.
Start checking PCH's RTC signals and U7800 at page 60.
PM_DSW_PWRGD must be high, if 3V3_S5 is present.
00840/75 are almost the same.
You should compare diode mode readings (red probe at ground), not ohm scale.
"and U7800 at page 60."
???
You should compare diode mode readings (red probe at ground), not ohm scale.
"and U7800 at page 60."
???
Start with U7800 (7 OF 10).
Also check 3V1_RTC (10 OF 10) at page 61.
Also check 3V1_RTC (10 OF 10) at page 61.
PMIC_EN_P3V3S5?
Check all resistors around U7800.
You may need to reball it...
Check all resistors around U7800.
You may need to reball it...