topic Re: EOS 40D Won't Power Up in EOS DSLR & Mirrorless Cameras

EOS 40D Won't Power Up

robinkaspar — Fri, 28 Jul 2023 18:42:43 GMT

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.

Re: 40D is dead?

Anonymous — Fri, 28 Jul 2023 13:16:16 GMT

Your camera has a date/time battery besides the camera battery. You could try replacing that battery. Your camera manual has the instructions on how to replace the date/time battery.

Re: 40D is dead?

robinkaspar — Fri, 28 Jul 2023 15:46:20 GMT

Well, duh! Forgot all about this battery and no one else I've asked has mentioned it. Thanks so much Bob, I'm back in business.

Re: 40D is dead?

Anonymous — Fri, 28 Jul 2023 18:41:24 GMT

Great to hear!

Re: 40D is dead?

MikeSowsun — Fri, 28 Jul 2023 20:08:06 GMT

This makes no sense. Are you saying you just replaced the Date/Time battery and your camera now suddenly works? I also have a 40D and it functions very well with the Date/Time battery entirely removed from the camera.

There must be some other reason why your camera would not turn on.

Re: 40D is dead?

robinkaspar — Fri, 28 Jul 2023 20:39:34 GMT

I wish I knew. But I replaced the date/time battery and inserted the other battery, fully charged, and the camera then powered up. So, it was the date/time by itself but the combination of the two. (I guess.)

Re: 40D is dead?

robinkaspar — Fri, 28 Jul 2023 20:40:00 GMT

*wasn't"

Re: EOS 40D Won't Power Up

normadel — Fri, 28 Jul 2023 21:10:20 GMT

This could be a case of a temperamental On/Off switch. On a (15-year) old camera, switch contacts can become corroded, even if it's just a light film on them. Repeatedly turning the camera on & off can wipe the film contacts clean.

An application of an electronics contact cleaner may keep it working for another 15 years.

Re: 40D is dead?

Anonymous — Sat, 29 Jul 2023 01:14:25 GMT

I've heard of others having the date/time battery cause this issue on other Canon cameras.

Re: EOS 40D Won't Power Up

shadowsports — Sat, 29 Jul 2023 01:27:29 GMT

My guess. The switch on the battery door might have been the cause. 🤔

Re: EOS 40D Won't Power Up

Canjunpharoah — Sat, 31 Aug 2024 20:35:01 GMT

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?

Re: EOS 40D Won't Power Up

lafrost30 — Wed, 26 Mar 2025 15:06:03 GMT

I am in a similar position with my Canon 40D. New batteries and charger bought and tried; replacement date/time battery bought and tried but still nothing. What is the next thing to try, please?

Re: 40D is dead?

LeeP — Wed, 26 Mar 2025 17:28:24 GMT

I had completely forgotten about the date/time backup battery given that my Canon XSi and T3i never once failed to power up. I passed both along with some EF lenses to a buddy that wanted to get into photography. I figured he could knock around with the dinosaurs a while until he got a sense of what he wanted to do before buying an expensive camera and then growing tired. The cameras have been a good catalyst for him. I will tell him that if they have this issue that I have a possible solution or two. Great thread to all who participated.

Re: EOS 40D Won't Power Up

John_Q — Fri, 28 Mar 2025 21:08:00 GMT

Hello lafrost30,

I'm sorry to hear that your EOS 40D will not power up.

Please make sure that you are using genuine Canon accessories for powering the camera. Also, make sure that all compartments on the camera are closed securely. Please check for debris inside the battery compartment where the pins are located and check for debris on the metal contacts on the battery pack. You may use a dry microfiber cleaning cloth to wipe the contacts. Try the camera with just a fully charged battery, no lens, memory card, flash, etc. Is the unit still not powering up? Unfortunately, that would mean there is a problem with the camera.

I've reviewed our service information and Canon no longer provides repairs for the EOS 40D. This camera is considered 'Out of Service Life' and parts are no longer available. I apologize for any inconvenience this may cause. You do have the Canon Upgrade Program as an option. The Canon Upgrade Program option allows you to replace your current equipment with a new or refurbished Canon unit at a discounted price. If you would like to take part in the Canon Upgrade Program, please call our Sales Department at 1-866-443-8002 from Monday - Friday between 9:00 am to 9:00 pm ET and they can help you with availability and pricing.

Re: EOS 40D Won't Power Up

gferdinandsen — Mon, 05 May 2025 13:45:08 GMT

I know this thread is two years old...But I recently was checking on my bodies for functionality and valid date/time...My 40D would not power up...so I charged the battery...still nothing...I ordered a new battery and charger...nothing still...Then I found this thread...I naturally bought a new CR 2016...still nothing...I'm at my wits end...It's not like I don't have newer and better bodies. I just wanted to dust off the old 40D. I may have to ebay it for parts only...

Re: EOS 40D Won't Power Up

IGourlay — Mon, 05 May 2025 15:34:41 GMT

This isn’t an attempt to help as such, but to explain. Some components on PCBs age badly if not energised at intervals. This was brought home to me when I read of a ham radio (I’m a ham radio operator too) that behaved rather like your camera, just refused to do anything at all. After an extended period of non-use. An explanation offered was that some of the electrolytic capacitors on the boards in the rig may begin to leak electrolyte from their cylindrical can-bodies. this electrolyte liquid can cause corrosion on conductive tracks, causing terminal shorts that can produce various malfunctions as well as possibly kill the machine stone dead. If that’s the case with your 40d, it’s down to parts other than PCBs only. Main components like controls, sensor, etc will remain ok. Radios that periodically get turned on even briefly don’t seem to suffer this nasty business. Possibly - cameras similar? Not very helpful, but a possible explanation that might give a bit of (!) closure?😉 I found my 40d to be the only body that I did not miss at all after its sale. It just didn’t do anything very well at all. Its replacement was an original 7D, my first new dslr. Still got it, works just fine - within its limits, that is. But I’ll not be selling it, it’d only fetch buttons anyway.

Re: EOS 40D Won't Power Up

LeeP — Mon, 05 May 2025 16:09:14 GMT

Fascinating.

Three years ago, I decided to dust off my Pentax ME and K1000--both were stored appropriately without batteries and shutters not cocked--I put batteries in and they've been good to go ever since. That opened the floodgates of going back to film--in addition to my digital work--with a healthy dose of G.A.S. (gear acquisition syndrome).

It never occurred to me that modern digital cameras could die from non-use despite correct storage, but your explanation seems plausible, though I admit I know nothing about electrogremlins (sic).

Thank you for the information

Re: EOS 40D Won't Power Up

normadel — Mon, 05 May 2025 16:20:52 GMT

I acquired a second-hand 40D a few years ago that worked for a while, then ceased turning on. Did some searching and found articles talking about the 40D being prone to this malady, with no fix.

Sometime later got hold of another 40D which also succumbed to this fate. Since then I've avoided the 40D as a model worth keeping.

A camera, like a computer (as I saw being Dell and Apple-certified service technician, and saw industry-wide in the 90's) can be the victims of defective components being made and sold all over the world, or sometimes by one specific company. An end-product manufacturer then gets in a bad situation not of their own making. They can repair or replace under warranties at huge expense, as happened with computers. Apple and Dell even extended warranties for problems of this nature. But there is a limit.

After that, parts availability is an issue.

Some products are lemons, plain and simple.

Re: EOS 40D Won't Power Up

LeeP — Mon, 05 May 2025 16:43:50 GMT

"Some products are lemons, plain and simple."

Very true.

Decades ago when I started out in photography, one of my cameras was a Pentax ME. It had a truly amazing meter and with +/-2 stops of compensation, manual was theoretically not needed--though I also had a manual body. The ME went with me all the time because it was easy to carry. These days I have an R100 as my with-me-all-the-time camera. The ME Super came along with trendy buttons to allow manual exposure, so I added a body. Though I never experienced total failure, the Super wasn't as unflappable as the standard ME which I still have. The Super--over time--suffered from glitchy buttons. Push the up button (increase shutter speed) once and either have nothing happen or it would jump two speeds higher. I got to the point that I stopped using it in manual. I later sold it.

In the Canon world, my Elan IIe was less reliable than my 7e. My T3i was less reliable than my XSi.

The plethora of models that a brand like Canon or Nikon must offer today along with the imperative to always have something new increases the chances of a lemon getting into the mix.

Thankfully, I've never had a camera completely fail.

Re: EOS 40D Won't Power Up

lafrost30 — Tue, 10 Jun 2025 09:17:29 GMT

Thank you John_Q, that seems to have worked! That has saved me a fortune in a new camera!