- No damage, the power LED on the programmer will blink indefinitely if the driver fails to power up, if the LED becomes solid, then you can attempt to flash.
- The wiring of the CH340N chip is different whether it’s powered with 3.3V or 5V, the V3 pin is connected to VCC (3.3V) in the 3.3V programmer. In a 5V/4.5V programmer V3 is not connected to VCC and decoupled with 100nF. I’m guessing V3 is the output of the 3.3V internal LDO of the chip, it probably wont like 5V on it (the datasheet isn’t really helpful here).
Here are two modifications (one or the other) one can do to the 3.3V programmer for flashing the D3AA if it has trouble with it.
- Cutting the 3.3V trace (shown in red) between the output of U2 (3.3V LDO) and the + pogo pin, then soldering a wire between the input of U2 (USB 5V) and the + Pogo pin (shown in orange). This will provide 5V to the driver and keep the CH340N chip powered by 3.3V.
- adding some output capacitance, for example with an electrolytic capacitor plugged into the header holes (blue), it should work without soldering, still 3.3V supplied to the driver, but the added capacitance should help with the inrush current.
