My RCA 300W Blu-Ray/DVD stopped working right after one week, I've only played two Blu-Ray's on it. The screen goes green and the speakers make an obnoxious noise. Totally frustrated.

SOURCE: rca 2250

Sounds like your right side output is shot. And yes it can be fixed, but the cost factor would be higher than what you paid for the set itself. First see if your inputs are working correctly, this also could be your problem. Check all your connections.

SOURCE: when i unplug my rca rt2250 home theater system.

this is the amp IC and while unplugging and plugging it in again helps reset the IC for a little while , it will eventually completely quit and will need replaced
make sure that none of the speaker wires(bare wires) are touching or look like they might be where they are connected at
also if turning up the volume makes it cut out or sound bad then this will also indicate a bad amp IC

SOURCE: I have a RCA RTB

If you have the availability to connect it to the internet via the network jack on the back of the console, please do this and run through the set up to make sure that your firmware, is correct and updated!

SOURCE: I can't get a signal

My suggestions here are to check your connections from your player to your tv. Make sure that if you are using the red, blue, green, red, white composite cables, that they are properly seated and connected. Next check your tv, and make sure that your cables are connected properly on the tv and that your tv is on the proper input. If you are using a HDMI cable and you still have no picture on your tv, there is a slight possibility that your cable could be bad. Hope this helps, if you still have no picture at that point I would recommend calling the support number for your device!