You can inject even 2V, but may need a thermal cam to detect snall temperature differences.
Remove CPU heatsink first...
Remove CPU heatsink first...
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A2141 820-01700-A no power
- Thread starter hgoncalves
- Start date
hgoncalves
Active member
Hi,
U8220 seams to be the only component that gets hot but even after removing it, the short remains, and PP3V3_G3H_T seams to also be shorted (0.003 in diode reading). U7800 also gets hot when injecting 2V on PP3V3_G3H_T.
I don't have a same model donor board.
Can I use the same components from a different model board?
U8220 seams to be the only component that gets hot but even after removing it, the short remains, and PP3V3_G3H_T seams to also be shorted (0.003 in diode reading). U7800 also gets hot when injecting 2V on PP3V3_G3H_T.
I don't have a same model donor board.
Can I use the same components from a different model board?
Last edited:
Yes, no problem.
hgoncalves
Active member
Hi,
Can you help with the board model. I can't find those components on otehr schematics. Do you know any other model?
Can you help with the board model. I can't find those components on otehr schematics. Do you know any other model?
Look at "Power FETs" page in other schematics.
You may find chips with different name, but same function.
You may find chips with different name, but same function.
Last edited:
hgoncalves
Active member
Hi,
PP1V8_G3S now has 0.250 in diode reading, but 0V. The power isen't cycling anymore, but it 's still at 5.12V and 0.26A
PP1V8_G3S now has 0.250 in diode reading, but 0V. The power isen't cycling anymore, but it 's still at 5.12V and 0.26A
Is it recognized into DFU?
hgoncalves
Active member
Hi,
No it isen´t recognized in DFU. However, I notice that with the battery conected it pulls 20.5V and 0A from ampmeter, on all USB ports, and without battery connected only 5.12V and 0.26A
No it isen´t recognized in DFU. However, I notice that with the battery conected it pulls 20.5V and 0A from ampmeter, on all USB ports, and without battery connected only 5.12V and 0.26A
Last edited:
Check if T2 gets all SLPS2R and AWAKE voltages, required for DFU.
Compare diode mode on its coils with good board.
Also check if R7835 is burnt.
Also check if R7835 is burnt.
hgoncalves
Active member
I can't find R7835. Only C7835. Are you sure?
All coils have low diode reading:
Diode reading Good board:
L7813 = 0.349
L7817 = 0.050
L7816 = 0.050
L7814 = 0.278
L7815 = 0.278
L7806 = 0.010
L7807 = 0.010
L7808 = 0.010
L7809 = 0.010
L7811 = 0.037
L7812 = 0.037
L7810 = 0.327
R7814 = 0.279
Diode reading bad board:
L7813 = 0.016
L7817 = 0.012
L7816 = 0.012
L7814 = 0.002
L7815 = 0.002
L7806 = 0.021
L7807 = 0.021
L7808 = 0.021
L7809 = 0.021
L7811 = 0.048
L7812 = 0.048
L7810 = 0.383
R7814 = 0.002
All coils have low diode reading:
Diode reading Good board:
L7813 = 0.349
L7817 = 0.050
L7816 = 0.050
L7814 = 0.278
L7815 = 0.278
L7806 = 0.010
L7807 = 0.010
L7808 = 0.010
L7809 = 0.010
L7811 = 0.037
L7812 = 0.037
L7810 = 0.327
R7814 = 0.279
Diode reading bad board:
L7813 = 0.016
L7817 = 0.012
L7816 = 0.012
L7814 = 0.002
L7815 = 0.002
L7806 = 0.021
L7807 = 0.021
L7808 = 0.021
L7809 = 0.021
L7811 = 0.048
L7812 = 0.048
L7810 = 0.383
R7814 = 0.002
Then no doubt, U7800 is burnt.
Sorry, I was looking at wrong schematic.
Check R7900 instead...
Sorry, I was looking at wrong schematic.
Check R7900 instead...
hgoncalves
Active member
R7900 seams to be ok and has 0 ohm resistance.
After replacing U7800 all the doils diode readings are likely the same.
After close inspection, I notice that U8250 seams to be a bit blown and is geting a bit hot on thermal cam. I don't have a donor board to it. Do you know other board model that I can use as a donor for U8250?
After replacing U7800 all the doils diode readings are likely the same.
After close inspection, I notice that U8250 seams to be a bit blown and is geting a bit hot on thermal cam. I don't have a donor board to it. Do you know other board model that I can use as a donor for U8250?
Last edited:
Check schematics from other models.
You may find it used for other power rails...
You may find it used for other power rails...
hgoncalves
Active member
I used one from other board model, but the problem still persists...
If you still have low resistance to ground on U7800 coils, then bad T2...