350D will not turn on due to damaged CF card.

Have found the back up battery,pulled it out for a few minutes and replaced both the back up battery and a fully charged main battery without success so I have pulled all batteries out for the night and will try again in the morning. By the way how do you suugest I "short" the back up battery? Thanks again for your help and will try again in the morning.

Shorting means to place something metallic across the two areas that form the battery terminals; both batteries should be removed when doing this. This in theory bleeds off any residual charge still in the camera circuitry. You can also bleed off the charge, again all batteries removed, by simply putting the on/off switch in the ON position, then hitting the shutter button a few times.

Again, I ask because you have't clarifed, have you looked at the pins in the camera body very carefully and verified that none are bent or even missing. On occasion a pin has been known to break off and remian in the card where it may not be readily visible.

poppy2 wrote in post #14577483
... By the way how do you suggest I "short" the back up battery? .

Nobody is suggesting you short the battery .. just the connections inside the camera where the battery sits (to drain residual charge left inside). Personally I don't think this step is required.

Perfect_10 wrote in post #14577751
Nobody is suggesting you short the battery .. just the connections inside the camera where the battery sits (to drain residual charge left inside). Personally I don't think this step is required.

You very well may be right, I didn't think it would be a big deal to try it (especially since the camera is 'tango uniform' already).

Today I put the "Backup" batteryback and fully charged up the main battery and put them both back into the camera and the little green start light came on but the camera did not start up. I turned off the camera and came back approx 20 minutes later and the green light was still "on" so then I removed both batteries. I will purchase a new "Backup" battery and try again.

John from PA wrote in post #14577503
Shorting means to place something metallic across the two areas that form the battery terminals; both batteries should be removed when doing this. This in theory bleeds off any residual charge still in the camera circuitry. You can also bleed off the charge, again all batteries removed, by simply putting the on/off switch in the ON position, then hitting the shutter button a few times.

Again, I ask because you have't clarifed, have you looked at the pins in the camera body very carefully and verified that none are bent or even missing. On occasion a pin has been known to break off and remian in the card where it may not be readily visible.

All the pins look straight and intact.

Today I purchased a new Back Up battery and tonight I tried the camera with a fully charged main battery and a new back up battery and the camera is still the same.Today I turned the camera off and the green light stayed on as it has been since playing up and I came back half an hour later and the green light was still on so I had to remove the main battery.

Chalk it up to a CF card being read by a reader and creating an issue, rare but it happens.

Sounds like a trip to a repair facility.

Thanks John for your input and it certainly does sound like a trip to the doctors and hopefully not a trip to the Undertaker.

Thanks everyone for all your suggestions, it has been very encouraging.

John from PA wrote in post #14582580
Chalk it up to a CF card being read by a reader and creating an issue, rare but it happens.

Tell me about it! That is why I now only download direct from camera, my card reader just turned uploading into a nightmare. It even renamed everything starting Canon100.......... so I lost my nice IMG_xxxx numbering.

Poppy it doesn't say where you are but my old 30D had the same problem cost me £80 to get it repaired it was the CF in the end , if you are in the uk i can send you there address there in luton and you can mail it to them as well instead of going there if it helps

How old is the main battery and do you have another main battery you can try? I've had a battery or two that has appeared fully charged on the charger, but when put in the camera was not able to power it on. Believe it has something to do with the internal resistance of the battery as it ages. Don't discount the possibility of the charger having a problem as well.

To answer 2 questions I am in Australia and to answer the 2nd question I have 3 main batteries that I use.

I'm curious to know if there's any difference in the symptoms if you don't put the CF card in the camera at all. If it runs without the card, wether you can reach the menu option to enable shooting without the card present & check the general operation (shutter / mirror etc)