Chosen Solution

So i have a old 360 from 2008 and it has the red ring and its code was 0102 which is the bad gpu joints and after following this guide on YouTube https://youtu.be/bqSKDluZMmY the rrod has changed to 0003 and its fan only spins for a second

The invader 2  0003 is either a dead GPU or no power going to the GPU. It all will depend how you did the “reflow”. Remember, that this is always a hit or miss. Ultimately you’d need a reball and a new IC since it is the actual chip design that causes the failure