Xbox freezing....

[Oyeve]

So, I havent been following up on the xbox 360 fiascos lately. I have 3 xbox 360s. 2 were used consoles that I bought years ago. One was bought brand new about 1 1/2 years ago but when I did the update last year the xbox just dropped dead. Everytime I reboot it it keeps saying that it couldnt read the HD to install the update. Called MS and they were useless. So, I have been using one of my older 360s since then. Well, yesterday while playing SR3 it froze. i thought it was just really overheated because I was taking advantage of the free weekend epix deal. I let it cool down for hours and when I turn it on and either start a game or stream a movie it freezes up hard. no error, just a freeze. Buttons dont work on gamepad so i have to power down. I recall reading about temporary fixes online years ago but there is so much info and googling just brings up stuff that IMO is BS. So, I am going on the assumption that the GPU is faulty/defective/unsoldered. Knowing the folks at AT have been dealing with this for years what is the best way to go about a DIY fix? Right now I am using a frankenstein 360 that I built from other broken 360s. It works but it is literally pieced and taped together.