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820-02020 stuck @5v
- Thread starter phantom
- Start date
i dont understand: is this problem related to the fact that i have unstable ldo and macbook cant switch to 20v?M1 MacBooks - LogiWiki
We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this arealogi.wiki
Once removed RD810, do you get correct diode mode reading at 3V3_S2?
Apart of bad Wifi chip, something else damaged...
why you say that? on PP3v3_S2.i've no short anymore...if i go with power supply on that line, nothing happen....so i think this line is fixed?!
soldering an 1.5UH-20%-12.5A-0.01OHM (just for test) in the place of lc710, i have 0,430 diode mode and higher resistence (i'm not able to read the value because it change continously...like from M to K)
but 3,3 is not stable
https://www.dropbox.com/scl/fi/4p5z...2-00.mov?rlkey=ulkqu7tudzu4cwqfskhjonmjm&dl=0
soldering an 1.5UH-20%-12.5A-0.01OHM (just for test) in the place of lc710, i have 0,430 diode mode and higher resistence (i'm not able to read the value because it change continously...like from M to K)
but 3,3 is not stable
https://www.dropbox.com/scl/fi/4p5z...2-00.mov?rlkey=ulkqu7tudzu4cwqfskhjonmjm&dl=0
Last edited:
"now i have 0,200 / 0,600k resistence to ground
openboard data says 0,400 /40m"
You've reported half reading of expected value.
Something else must be affected.
Now you say to have 0.430; not sure which value is real...
openboard data says 0,400 /40m"
You've reported half reading of expected value.
Something else must be affected.
Now you say to have 0.430; not sure which value is real...
Probably previous reading was bad.
The value can't increase if you connect something more there.
Ohm scale is usefull for very low values, under 0.010 in diode mode; don't bother with it in this case.
P3V3S2_EN fluctuates?
The value can't increase if you connect something more there.
Ohm scale is usefull for very low values, under 0.010 in diode mode; don't bother with it in this case.
P3V3S2_EN fluctuates?
PPBUS_AON and 3V8_AON are stable?
Also check U8100 and U7700 LDOs.
Also check U8100 and U7700 LDOs.
PPBUS_AON 12,2v stable and 3V8_AON 3,7 stable
on u8100
PP1V2_S2 0v floating 1,2
PP3V3_S2_UPC floating 3v/2,5/1,6/0
PP1V8_AON_MPMU 1,7
MPMU_VREF_ADC is 0,020v
on u7700
PP0V72_S2_VDD_LOW 0v
PP1V2_AWAKE_PLL 0v
PP1V8_AON_SPMU 1,7 stable
PP0V855_S2SW_CIO 0v
PP0V805_S1_VDD_FIXED 0v
PP1V2_S2_CIO 0v
on u8100
PP1V2_S2 0v floating 1,2
PP3V3_S2_UPC floating 3v/2,5/1,6/0
PP1V8_AON_MPMU 1,7
MPMU_VREF_ADC is 0,020v
on u7700
PP0V72_S2_VDD_LOW 0v
PP1V2_AWAKE_PLL 0v
PP1V8_AON_SPMU 1,7 stable
PP0V855_S2SW_CIO 0v
PP0V805_S1_VDD_FIXED 0v
PP1V2_S2_CIO 0v
May have bad solders on U8100, or even bad chip.
Also may have problems with a secondary voltage.
Check all power rails in diode mode; start with LC320.
Also may have problems with a secondary voltage.
Check all power rails in diode mode; start with LC320.
You've got better diode mode reading after removing RD810, which isolated Wifi chip; so that is bad.
I sent you the link to understand what suppose this.
Spikes on 3V3_S2, caused by feedback circuit, can damage CPU.
Now you report bad reading even on 3V8_AON, which is main CPU's power.
Looks like bad CPU...
I sent you the link to understand what suppose this.
Spikes on 3V3_S2, caused by feedback circuit, can damage CPU.
Now you report bad reading even on 3V8_AON, which is main CPU's power.
Looks like bad CPU...
)
You may have two good in stock now.