50d aoto focus fuse issue ?

1st of all, thanks to the forum for info so far, much appreciated.

From previous threads, it appears that the fuse for auto focus is r/s in my 50d. (It just does't even attempt to AF at all) . Just wondering which PCB the fuse is on so I can order a replacement.

The main board or the bottom one ?

Name: 50d Main PCB .jpg Views: 18 Size: 18.9 KB
Name: 50d Bottom PCB.jpg Views: 18 Size: 33.4 KB

Thanks,
Wooky from DownUnda

I'd let Canon Service have a look at it before jumping to a conclusion without an expert opinion.
It might be nothing to do with a PCB.

Are you planning to replace the PCB board and test everything yourself, that would be fraught with danger unless you have the service manual for the 50D handy.