Re: TC Impact Twin mods
That's very helpful.
If I understand correctly then, at initial power-on, if the digital supply doesn't spin up, the MCU will never boot, and therefore the analogue supply will never activate. This would explain why neither switching supply is spinning up.
I therefore first need to understand why the digital supply isn't spinning up. Looking at the schematic, it appears that the switched 3.3V output rail is what provides the shunt regulator feedback for the digital supply switcher. I'll first check the output filter caps C518, C517, C576 and C575, and then go from there.
That's very helpful.
If I understand correctly then, at initial power-on, if the digital supply doesn't spin up, the MCU will never boot, and therefore the analogue supply will never activate. This would explain why neither switching supply is spinning up.
I therefore first need to understand why the digital supply isn't spinning up. Looking at the schematic, it appears that the switched 3.3V output rail is what provides the shunt regulator feedback for the digital supply switcher. I'll first check the output filter caps C518, C517, C576 and C575, and then go from there.
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