My Camera is not switching on

@joeleedope the problem that you are having, is that you have a known-broken part. That could shorten, or at least prevent the camera to turn on. My suggestion would be to fix that part first. I am not sure if you had your camera disassemble to repair the CF reader. Just in case, use something like this video or even https://www.lifepixel.com/tutorials/infr... up to step 17. Of course you can also use the Canon EOS 350D Disassembly instructions for your camera. The reader is soldered to the main board. You may have to get a donor board to transplant the reader or even try to replace the pins. Replacement boards are available at places like ebay.com for ~USD$30 (looks like you will have to do some chores to make some $$)

Now, while you are working on your camera to get it back into shape, it is always good to replace the RTC battery (its a CR2016) That would also test the theory that this will enable you to restart your camera.

Now, one more thing and it may just be important. There are at least two fuses on your motherboard. One of those is a power fuse. So, take a very careful look at the board component. You may find it, since it should have a P printed on it. If you can't find it, post some really good pictures of that circuit board (both sides) with your Question. Remember that we will have to enlarge it, so please make sure it is a well focused, large enough image. Ajout d'images à une question existante

None of this is really complicaed or to complex. Just take your time and study everything first before just tearing it down. You got this!