ameasere
New member
I have an A1932 820-01521-A board that came in for no power. When tested, it did power but no chime/backlight/fan spin.
It was stuck at 5V and the meter kept cycling - 5V 0.2A then resets. Inspection showed U3000 had a hole blown in the middle of it, so it was replaced. No more cycling issues!
It then got stuck at 5V 0.23A, no cycling nothing. Many attempts to see if DFU mode was available were unsuccessful - keyboard combination and jumper methods yielded nothing.
Now, the board does get to 20V but has some strange behavior. It will go to 5V 0.23A for a few seconds, and then gets to 20V 0A with a very very slight fan spin then stops. After a few more seconds, it will push to 20V 0.25-0.3A and ridiculously loud fan spin with no chime/backlight/DFU. I can do what appears to be a power cycle using the power button - even when holding the DFU combination - the meter goes back to 0 and starts the process again if I hold the power button long enough. All of the tests were done both with and without battery connected, and with all cables connected and disconnected to ensure I wasn't just being silly.
Power rails show normal voltages:
I am unsure if 20v has gone right through somewhere it shouldn't have, like the CPU or the T2 chip - the T2 does get warm but nothing out of the ordinary under thermal camera (34 degrees Celsius maximum), CPU is stone cold.
Both USB-C ports exhibit the behavior above, the CD3215 looks visually fine and has no obvious signs of damage (and no holes, like U3000 had).
It was stuck at 5V and the meter kept cycling - 5V 0.2A then resets. Inspection showed U3000 had a hole blown in the middle of it, so it was replaced. No more cycling issues!
It then got stuck at 5V 0.23A, no cycling nothing. Many attempts to see if DFU mode was available were unsuccessful - keyboard combination and jumper methods yielded nothing.
Now, the board does get to 20V but has some strange behavior. It will go to 5V 0.23A for a few seconds, and then gets to 20V 0A with a very very slight fan spin then stops. After a few more seconds, it will push to 20V 0.25-0.3A and ridiculously loud fan spin with no chime/backlight/DFU. I can do what appears to be a power cycle using the power button - even when holding the DFU combination - the meter goes back to 0 and starts the process again if I hold the power button long enough. All of the tests were done both with and without battery connected, and with all cables connected and disconnected to ensure I wasn't just being silly.
Power rails show normal voltages:
- PP5v_G3S: 5v
- PP3v3_G3S: 3.3v
- PP1v8_G3S: 1.8v
- PP3v_G3H: 3v
- PP1v8_AWAKE: 1.8v, Present
I am unsure if 20v has gone right through somewhere it shouldn't have, like the CPU or the T2 chip - the T2 does get warm but nothing out of the ordinary under thermal camera (34 degrees Celsius maximum), CPU is stone cold.
Both USB-C ports exhibit the behavior above, the CD3215 looks visually fine and has no obvious signs of damage (and no holes, like U3000 had).
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