Canon EF Film Camera Issue - Battery check light always on

[Minto]

Hello folks! I come to you with an issue with a Canon EF body. Everything seems to work correctly, except for the battery check light is constantly on, even when the power switch is turned to off. I've cleaned the battery terminals of any corrosion, and also given the battery-test circuit a bit of a cleaning too but nothing seems to be solving the issue. Has anyone else had the same problem? I found a wonderful service manual, but honestly I'm not sure what part of the circuit is acting up. Any help would be much appreciated. Cheers then! -Jonathan

 

[koraks]

Which body is that?
I've got one with a somewhat similar issue; it's an EOS30v. It does power up OK, but the battery indicator always indicates an empty battery.

 

[Kino]

I haven't worked on one of these cameras before, but after glancing at the repair manual and seeing the battery check button is on the bottom plate, I would remove the bottom plate and check for corrosion or loose parts bridging the contacts.

 

[Minto]

Which body is that?
I've got one with a somewhat similar issue; it's an EOS30v. It does power up OK, but the battery indicator always indicates an empty battery.

“The Black Beauty” from the 70’s!

 

[Minto]

I haven't worked on one of these cameras before, but after glancing at the repair manual and seeing the battery check button is on the bottom plate, I would remove the bottom plate and check for corrosion or loose parts bridging the contacts.

View attachment 351823

Thank you Kino! I have already looked around that area and have failed to find any bridged contacts yet. I’ve also checked the top side of the camera around the LED to see if there’s anything making contact that shouldn’t, but no luck so far.

 

[Kino]

According to the repair manual, the LED is supposed to flash during slow exposures and when you push the battery check button.

Maybe this indicates something much deeper in the camera body itself. Sorry, out of quick-fix ideas; best to check with a camera repair technician.

 

[koraks]

“The Black Beauty” from the 70’s!

Sorry, I totally misunderstood. I thought you meant an EF-mount EOS camera, but you're referring to the actual EF. My bad!

 

[Chan Tran]

I have 2 EF bodies. 1 works correctly and one doesn't. The one that doesn't would work only if I install only 1 battery. It would work and the meter as well as the shuter priority auto exposure work except that the slow shutter speeds don't work. It's kind of strange. I hope the OP get it fixed. The EF is a very nice camera I like it much better than the AE-1.

 

[RAY WILSON]

OP, I hope you get your camera sorted. I didn’t even know the EF existed until I stumbled across one at a flea market. Snapped it up for a ridiculously low price and only later came to realise what a jewel I had found. Good luck.

 

[Chan Tran]

OP, I hope you get your camera sorted. I didn’t even know the EF existed until I stumbled across one at a flea market. Snapped it up for a ridiculously low price and only later came to realise what a jewel I had found. Good luck.

I got my EF (the one that is working) from a friend for a very good price. When he went camera shopping in 76 he was looking for the AE-1 but the store had an EF and they dropped the price a lot to make it a lot less expensive than the AE-1 so he bought it. But only short time after that he felt regretted not buying the AE-1 so he bought the AE-1 and sold me the rarely used EF for next to nothing. I later did have the AE-1 but I like the EF a lot more. Even without battery the EF can be used with almost all the shutter speeds. Slow shutter speeds really not important because you can accurately time them in B.