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Issue #2 - Board begins to boot, but then shuts off after a few seconds.
Solution #1 Solution #2 - This may be a result of X_PWRON being toggled low for too long, triggering a 'long press' at the PMIC (typically a few seconds). When a long press is detected the PMIC will transition the system to the OFF state. The X_PWRON low time, T4, can be adjusted by decreasing the values of R2 and C3.
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