Hello, I have the special edition halo slim xbox and am using HDMI cables. The last couple days every so often I would see my console was lagging a bit. I was playing LA Noire and as I was driving down the street, textures weren't loading fast enough and such. It seemed to resolve itself after restarting my xbox so I forgot about it. A few days later I loaded up Full House Poker, and it was having trouble in the opening menu, for example the music was off beat, and the textures in the background were moving to slow and laggy and after a bit, this resolved itself as well.
However today I turned on my xbox and opening the dashboard too forever, and then when I tried loading Hulu Plus, it gave me a blank black screen and froze. I restarted the xbox and now it gives me the same black screen but I can use the guide. I used the guide to go back to the dashboard, but doing so makes it freeze for about a minute and then kicks me to the dashboard. So I tried Netflix and it does the same thing. So then I tried LA Noire and it loaded up fine. (it may have took a bit longer than normal, I am not sure)
Anyways, I deleted the harddrive cache, and restarted the xbox, and it is still doing the same things. It even goes as far as offering me an update to Hulu (because I deleted the cache) that I accept, it downloads, and still keeps me at the black screen.