Hooking laptop to onkyo sr604 through hdmi no sound through stero

hdmi sockets are faulty on the dsp board - repair - replace dsp board

Check the Ohm value (4, 8, 16...) on the speaker and on the ONKYO too.
If not the same that is the (big) problem!

You said you tried hooking the HDMI up directly from the TV to each component, and that worked. How is it usually hooked up - through some kind of switch? I'm not completely understanding your setup here.

It's usually the hdmi switching IC that goes bad on these. Not something you can really replace without the right equipment and knowledge.

I have researched on your issue and found that the Receiver is not capable of processing audio from HDMI input. It will bypass the signals from its HDMI input to HDMI output..
The Receiver has 3 HDMI input and one output. Hence you can use this as a HDMI switch to connect three HDMI devices to single HDMI port on the TV.
In order to get the sound from speakers connected to the Receiver, it is required to make alternate digital or analog audio connection.
You can confirm the information from the manual of the Home Theater System. Please refer page # 36 of the Manual to get the information. I have provided a link where you can download the Manual for the HT System:
http://a248.e.akamai.net/pix.crutchfield.com/Manuals/580/580HT5100B.PDF

Check to make sure the speakers are secure, if everything is fine! the problem is in the audio output ic's in the receiver. This will need a technician to take it further to find out how much the cost will entail.

easiest fix is to take all hdmi straight to tv. then come out of tv with optical cable to your receiver. that way what ever your watching will automatically be sent to the receiver thru optical. you even will get dolby dig. also you can have audio from your tv when you dont want to use your surround. keeps receiver on one input also.

http://www.devicemanuals.com/guide/AV%20Receiver/Onkyo/Onkyo-TX-SR604-Owner's-Manual-English-TmpnNU56RT.html

it is very frustrating... I just have discovered today. I can't solve this because my Itunes mac is only digital audio output, I can share its sound to Zone 2..

I suspect an open ground or bad cnnection in your hdmi cable to the amp from the sat.A hum is very indicative of that situation