This error usually occurs when you try to open your console and try to add something up where you need to really take off the screws and disassemble your system. I was able to fix my game console by following some guides through this site http://www.xboxredlight.com/
It is strongly advised that every time that you dismantle your system, you should properly return all parts and screws together with the added part or the replaced part to its correct places. Screwing back the screws is also very delicate that once you tighten it too much, this will result to the error 0020. This denotes that the screws are very intact and the pressure that it exerts towards the board has a great impact to the flow of data and current in your console, thus, resulting for the error to be prompted to you. Try logging on this website I was able to fix my game console by following some guides through this site http://www.xboxredlight.com/
If you tend to replace parts in your computer, making use of the very popular X clamp method and other solutions, you have to assure yourself that you know what you are doing, or you just might get into a bigger trouble for what you just did was wrong. So be very careful.
Another simple solution for this error code 0020 is to try and remove your hard disk for a few minutes, might as well do the same for your memory card. You may want to disconnect also the cables and let your game console rest for a few moments. After letting it rest, try to reconnect everything properly and tightly, but not so much and leave the hard disk unplugged. If this will result to a success, there is a great possibility that your hard disk is plugged in too tight or it is about to overheat. This also again falls that the possibility there is a burnt chip that is residing in your system board.
Trying this work around several times may either result in a success or failure with the error 0020 with your Xbox 360. More solutions and suggestion you can find on this site http://www.xboxredlight.com/
