40D won't turn on

[Twizzel]

Anyone got any ideas? My brother dug my backup 40D out of my bag today and put his batteries from his 50D in it (gripped). It apparently wouldn't turn on. It's sat in my bag for a year since I bought my 7D and I haven't had to use it since... before I bought the 7D I used it fairly heavily every weekend (horse events).

Any ideas why it wouldn't turn on? will charge up some of my batteries and try it without the grip but I'm a bit perplexed...

 

[tijuana taxi]

Try taking all the batteries out including the little button one then leave it for an hour or so before reinserting them and trying to turn it on

If no joy it could be the DC/DC board, basically a fuse that has blown which would need a trip to a service centre for repair

 

[4wd]

Battery door needs to be fully shut?
I wonder if it can't 'boot' if the internal battery is dead.

 

[admirable]

Sounds a bit like my wife!