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Macbook Pro A2338 820-02020 3V3_S2 missing
- Thread starter Instafixx
- Start date
Check all feedback resistors RC709-13.
Be sure to have good solders and traces.
Be sure to have good solders and traces.
High value resistors can't be properly checked onboard.
Move them a bit, letting one pin free; this way makes the test easy.
"Traces look fine"
Tested in buzzer mode (until UC710)?
You can test removing CC719/20; possibly corroded.
Move them a bit, letting one pin free; this way makes the test easy.
"Traces look fine"
Tested in buzzer mode (until UC710)?
You can test removing CC719/20; possibly corroded.
Instafixx
Active member
When everything is connected. the fan goes max instantly and then reboots after sometime. macbook detects on AC2 with a padlock sign.
Tried DFU Revive. Stuck at Installing Software Midway with Fan spin at max. Then eventually it got cancelled automatically.
Now it is stuck at 5V. No Fan Spin. Not detecting in AC2.
PPBUS pulsing from 11 to 12.3v every 2 seconds
Tried DFU Revive. Stuck at Installing Software Midway with Fan spin at max. Then eventually it got cancelled automatically.
Now it is stuck at 5V. No Fan Spin. Not detecting in AC2.
PPBUS pulsing from 11 to 12.3v every 2 seconds
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You've said UC710 gets power and enable; it should generate 3V3_S2.
Just in case, replace CC714; also try another UC710.
Did you check XWC711 too?
Just in case, replace CC714; also try another UC710.
Did you check XWC711 too?
If UC710 gets enable, it should work...
Instafixx
Active member
Replaced UC710. Now i get 3v3_s2. But machine still draws only 5V. it tuens and goes into recovery with wireless KB/TP icons coming up first though both seem to work. If i restart it will show the logo and the loading bar will go upto 25% and then reboot again into recovery. No FAN spin as well.
Will not enter DFU with button pressed.
Is it because of the auto cancelled DFU that happened previously?
Will not enter DFU with button pressed.
Is it because of the auto cancelled DFU that happened previously?
Instafixx
Active member
Pulled SOC_FORCE_DFU to 1.2V via jumper from PP1v25_s2 still not detecting in AC2.
It will only run on a charged battery and not on only charger.
AMP Meter Reboots every 2-3 seconds on both ports.
and not detect in USB. i think issue with the USB C ports maybe?
It will only run on a charged battery and not on only charger.
AMP Meter Reboots every 2-3 seconds on both ports.
and not detect in USB. i think issue with the USB C ports maybe?
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Check diode mode readings around CD3217 chips; compare with good board.
For DFU mode, I recommend external switch method:
logi.wiki
For DFU mode, I recommend external switch method:
DFU Mode Restore (Macs) - LogiWiki
We have Apple MacBook and iPhone Diode readings and general fault finding information compiled by the leaders in this area
Bad UC710 probably caused overvoltage into 3V3_S2 power rail...
Machine still works with charged battery?
If yes, try another CD3217 kit.
If yes, try another CD3217 kit.