RGH Xbox 360 No longer works through Sony A/V Amp!. HELP

[BlockABoots]

Today i bought a 3 way power HDMI switch, like this one...

As i have 2 hdmi cables i use on my xbox 360 (1 for capturing and 1 for normal play), anyway the device appeared not to work no lights on the device and no picture on my LCD, so i unplug the device and plugged my hdmi cable coming from my Sony STR_DH800 AV amp back into the Xbox 360 but i still wasn't getting a picture on the LCD, then the feeling of dreed starting to come over me as i guessed that the 3 port hdmi switch might have blown something.

I think i have covered all bases,

Xbox & HDMI cable works when plugged directly into the LCD - So not the cable or Xbox 360.
My PS3 Console works on the amp - so not the amp itself
My PS3 Console works on the HDMI input that the 360 was using - so not the HDMI socket on the amp

I have tried 3 different hdmi cables but still no picture, im not even getting the HDMI icon appear on the amp when i select the xbox 360 input on the amp so its not even detecting a HDMI signal...BUT i have notice that if keep unplugging and plugging in the HDMI cable on the rear of amp the HDMI icon does eventually appear but i still dont get and sound or picture.

EDIT: Have have now tried my brothers Xbox console on the Sony Amp using the same HDMI cable an HDMI input and his Xbox 360 get a display fine, so it must be my xbox, but i cant understand why the xbox works fine when i plug it straight into my LCD TV using the exact same HDMI but wont work when i plug it into the amp. Any ideas what could cause such an issue as because HDMI is digital i thought it either works or it doesn't there's no middle ground!?

 

[MasterChief]

Try checking display settings on your brothers 360 and compare them to yours.

Maybe his console is set to 1080p and your console is only set to 720p. Just another thing to rule out as its very strange one console works and the other does not.

 

[BlockABoots]

Yeah i have tried 480p, 720p and 1080p and i dont get a signal through the amp at all. I cant understand it as i would have thought if i get a display via the TV then i should via the amp aswell, i cant figure what would be different between the LCD and amp to make one work and not the other.

That 3 port HDMI switch must have done something but not sure what, but something not so bad as to bugger the HDMI socket altogether otherwise i wouldnt be getting a display though the LCD TV

 

[InsaneNutter]

What about if your power the 360 on with it connected to the TV, then disconnect the 360 from the TV (when its still on) then connect it to the amp / splitter and see if you get anything then.

Very strange problem that is, i was thinking it could be a 50/60hz problem as i know the VGA cable can not do 50hz, however HDMI should be able to do either perfectly fine.

 

[BlockABoots]

I'll give it a go when I get home. I've heard of HDMI sockets completely crapping out and stop working but nothing like this before, I can't think what would even cause such an issue, could be something to do with the digital 'handshake' the HDMI makes with the console & amp!?. The 360 is defo detecting the HDMI cable as the ring of light lights up and detects the pad usually if there is no video cable connected the ring of light doesn't light at all. It's also strange that I can get the HDMI icon to appear on the amps display of I unplug and plug back in the HDMI cable on the rear of the amp a few times but I still can't get sound or video

This has got me completely stumped, the obvious suggestion would be its a software setting on the 360 but I havent actually changed any settings prior to this happening! Cant understand why the 360 works when connect straight to the tv, ps3 console works on the amp using the same HDMI socket and cable and my brothers 360 works fine oon the amp using the same cable and HDMI socket....so it has to be the 360 at fault right?

 

[BlockABoots]

Ok the plot thickerns on this one, yesterday I took my 360 and HDMI cable around my mates to try it on his Yamaha amp and it totally worked fine, got a display straight away!. So now I'm really confused as I was sure it was some minor fault on the 360 but this would suggest its now my amp...or is it both. Is it possible some very minor fault occured on both HDMI ports (360 & amp) that now when they are paired together they can no longer work together but use them with any other device and they will be fine. Is this even possible!?, as at the moment it's the only plausible theory I can come up with!?