I got a v.1.0, I got the MAtrix flashed with Xecuter 2.6 bios
I aligned the chip so it flashes green
Turn off the Xbox. Put the switch 1 to off and start the power again but it wont boot, instead the eject light flashes red, and the box starts 3 times. What's wrong?

I have seen this problem several times with my matrix as well as other matrix chips. It turns out that sometimes the matrix will flash green even if it is not completely aligned (defeats the purpose of the led, i know...) Anyway, we finally solved it by soldering the bastard in there. Worked great after that. But b4 you do that, I suggest using an older 256k xecuter bios and seeing if that works first, because you can get the exact same problem with bad or no bios on the matrix.

Im having the same problem, boots 3 times, then blinks red and yellow. Not sure why??

It has to be a bad Bios....trying reflashing it with the PC connector kit. If you think the bios is good then, your connection isn't aligned right.