EOS 40D Won't Power Up

[robinkaspar]

I have a 40D I haven't used since I bought a 70D when it came out. The 40D has been stored in my bag in a closet without a battery, CF card, lens (body cap only), without anything that could render it useless. I brought it out of storage (not a hot attic, etc) in preparation to donate it to a worthy cause. It won't power up with the original Canon batteries (fully charged according to the original Canon charger). I bought 3rd party batteries which won't power it up. I bought a charger for those batteries and still the camera won't turn on. I can't think what else to try. My plan was to format all the CF cards I have and donate them along with the camera. It looks perfectly normal, the battery contacts look clean. What do I do with it? I don't want to invest any more money in it. 

[Canjunpharoah]

I have a similar problem. My 40D has not been used in years and was trying to get it up and running again. I tried all these steps replacing the 2 batteries and the memory card and still cannot get the 40D to power up. Any ideas on what to try now?