A very smart guy who goes by the nick “ameel” discovered an interesting and unusual solution to the unreliable boot times problem that all current glitching solutions suffer from on slim Xbox 360s.
The problem with glitching slim consoles resides in the need to send a glitch signal with some very precise parameters that are hard to control on the simple XC2C64A cpld, especially due to the higher clock frequency and the currently used injection point.
Increasing the wire length “fixes” this problem probably due to the added distortion, ringing, etc. that is added to the glitching signal. This will have to be analyzed in more details with the right equipment.
For the moment being, what’s important is that it’s a possible fix that many people seems to be very happy with, so we give our warm congratulations to “ameel” for this ingenuous solution!
Original thread available here
For everyone installing a Matrix Glicher in a Slim Xbox360, simply make the wire for PAD A of a length of between 25-30 cm.
Everything else is unchanged.

Thanks to tests made by great members of xboxhacker, we are able to bring you today a boot timing optimisation for Xbox Slim.
Indeed, even if on FAT boots are in instant, on Slim its were very random. The average of boots on Slim was about 30s to 50s on our great x360glitchip, but could take longer (2min) on few xbox.
With this optimisation, very simple, the boot on Slim goes down around 10s, and this at each boot.
You need for this, a AWG-30 wire of exactly 32cm, which will put between Point A of our x360Glitchip and the CPU_RST point under the motherboard. (This is the original installation point, only the lenght of the wire changes).
This optimisation, which could seem too simple, brings you amazing results.
It’s done, you are ready for a perfect Glitch now.