sorry for the spelling I am dislex..... Some things to try; 3 ways to RESET 1) in the "Custom Settings Menu" the first item is "RESET" 2) hold the +- and AF buttons for more than 2 seconds 3) turn camera off remove the battery 10 seconds , replace battery and turn on. 4)press the reset switch next to the DC in, USB and Video out ports. if none of the above work then there is a hardware problem. As for trade depending on where you trade (if the place fixes cameras) then there may or may not be a lose in how much you get. I'm not shoure tradeing for a D90 would be much of a upgrade and it may be cheeper to get the D80 fixed and continu using it or a year or 2.
There is very little room in any MAC and any space there is may be of a strange shape. So to start with what MAC do you have? and what sort of space do you need? (I am sour that defiant MACs have different amounts and shapes of space) The best way to find out if you can fit the mod you want to do would be to follow the guides on this site for disambly of the MAC you have and look for your self.
Update to my problem. I gote two new batterys for my MBP and did a test! re-installed OS X 6 Installed one of the new batterys. The battery lasted over 3 hours Alowed OS X 10.6.0 to update 10.6.8 Over the next 4 weeks I run the MBP on the battery 3 times a week never letting it drop below 20min (As the battery was less then a month old did not cycle it). By the end of the 3rd week the battery was lasting less the 40min's Re-plased the battery with the other new one. It's now been over 3 months and the battery is still OK This would suggest that there is a update between 10.6.0 and 10.6.8. that changes the farmware in the battery that afects the way is charges or discharges or re-ports charge. My suggestion is if you are updating to any update in the 10.6.n range then remove the battery while doing the update.
I have a similar problem with my MackBook Pro 15" old type (1.8Ghz). The battery was replaced at an Apple store in June 2010 after developing the won't hold much charge problem after a OS X update I believe about 10.6.6(I did not tack note at the time the problem devleoped). It was replaced befor reaching the state of the new one. The new(current) battery worked fine until I had to reinstall 10.6 and it auto updateed to 10.6.7. I don't know how but it appears that one of the updates changed something (perhaps firmware) that caused the battery to fail in the same sort of way. The problem I have is I now live in Greece and can not return to the Apple store that replaced battery. According to Apples website Greece dose not exist so getting a new replacement is a problem. System Profiler Manufacture: Sony Device Name: ASMB012 Pack Lot Code: 0001 PCB Lot Code: 0000 Firmware Version: 0110 Hardware Revision: 0500 Cell Revision: 0303 Charge remaining (mAh): 0 Fully charged: yes Voltage (mV): 8681 CoconutBattery...