With the new dashboard update 14717 or14719, the way used to disable the RGH chip does not work any more. After the update you have to physically disconnect the +3.3V from the the RGH chip to be able to boot oringinal nand. Adding a switch is a simple way but a little messy as you would have to drill a hole on the Xbox360. Some people used a 3.3V relay instead of a switch. But 3.3V relay is not easy to find.

Here we have an electronic solution for the swtich without using a relay or physicall switch. It consists of 2 transistors and 1 resistor as show in picture below:



When the level of pin 2 on Cygnos switch that used to disable RGH chip is Low, its to boot stock nand and High to boot RGH nand. So, when the pin is on High, it turns on Q1 making the base of Q2 low , which in turn switch on Q2. The RGH chip then gets +3.3V power via Q2 that connected to +3.3V rail. The 10K resistor is used to limit the current when Cygnos swith pin2 is on High. it works perfect when tested on a slim Xbox360.