5D mk ii Wont Power up, gives a red light

I received a 5D mk ii recently that was not working. Initially, I checked the basics; batterys charged, CF card, and such. I found one CF pin bent and was able to re-align it with a fancy tool that I made.

Now, when I push the battery grip in (with 2 fresh batteries) WITH the power switch ON, I get a couple flashes of the red power LED, but still nothing else.

Thoughts?

sdmaas said:

I received a 5D mk ii recently that was not working. Initially, I checked the basics; batterys charged, CF card, and such. I found one CF pin bent and was able to re-align it with a fancy tool that I made.

Now, when I push the battery grip in (with 2 fresh batteries) WITH the power switch ON, I get a couple flashes of the red power LED, but still nothing else.

Thoughts?

Click to expand...

I presume you’ve tried it without the battery grip just to rule that out?

my best guess is the internal lithium button cell battery (CR1616 I think) may have died and needs replacing. You’ll have to search online for how to do that on the 5DMKII.

It’s the small round cell battery that keeps the settings and clock going in the camera.

I pulled the clock battery and it registers 3V as it should. The camera turned on with a 7D mk i CF card w/MagicLantern on it (figured I would try it since the camera came with a CF card with ML on it). When it turns on with the 7D card, it only shows a Magic Lantern title screen that says "incorrect build for this model" which it should since it's from a 7D ML build. Im starting to think the previous owner bricked it while installing ML?

After hours of tinkering, I found the best "configuration that gives the most signs of life" ???

-Clean CF card format in working camera
-ML files from 7D mk i copied to CF card
-All 7D ML files replaced with 5D mk ii files (remaining files kept on CF card)
^^^^In this configuration, the ML prompt displays "Wrong Modules, This is not a 7D." message^^

Then:
-Replaced (7D) autoexec.bin with 5d mk ii's autoexec.bin file

At this point, I get the red LED to light up if I open the battery door, CF door and when putting on a lens.... but no LCD or any functions.

--
"It's not the gear, but the ear"
(or eye)

when you pulled the clock battery did you follow the instructions to perform a hard reset?

pull the battery out and then press the shutter button multiple times in order to drain any left over power, then replace the batteries and power the device back on. This will have performed a hard reset.

i have no experience using magic lantern software so can’t advise there.

I have done a hard reset as you described. Would this be a PCB issue? I'm finding info on a SMD fuse behind the LCD being a common issue, but I don't know how comfortable I am doing that fix...

Using some 3rd party software, I was able to extract a "rescue" file from the camera. In this process, the LCD was fully functional, as was the CF reader since I was booting the file extraction from the CF card. Now I'm just waiting to have the file deciphered. Does anyone have experience with bad PCB and are these symptoms of a bad PCB?

sdmaas said:

I pulled the clock battery and it registers 3V as it should. The camera turned on with a 7D mk i CF card w/MagicLantern on it (figured I would try it since the camera came with a CF card with ML on it). When it turns on with the 7D card, it only shows a Magic Lantern title screen that says "incorrect build for this model" which it should since it's from a 7D ML build. Im starting to think the previous owner bricked it while installing ML?

Click to expand...

MagicLantern software is not as good as many of us like to think. I use a Canon 5D Mark II and when I read about this software, I got excited, as probably many Canon user did, I ignored the warning on the download website that warns us - rightfully so - that the software can turn the camera into a brick. It sure did mine.

I could never get the camera loaded with Magiclantern software to work normally, ever. Kept hoping that the programmers of this software will soon succeed writing a flawless program while I kept experimenting with different versions. Never happened.

My last attempt to use my 5D Mark II with MagicLantern latest version was on May 1, 2020. Not only it locked up my camera, but it also fully drained a fully charged battery in about 40 seconds. Before the battery was fully drained, the Live View turned on without me initiating it, the mirror locked up also by itself, and the LCD turned black. At that point, I noticed that the battery was empty.

My assumption now is that MagicLantern Canon software is an amateur, childish hack. As it is with all software where no one stands behind their product. I should have heeded the warning that MagicLantern software can turn my camera into a brick before the download.

Don't be like me. If you like to hold a brick in your hands, buy a brick, it's cheaper.

If you want a camera that does what Magiclantern was supposed to do, spend the money. There is no free lunch.

Have you tried turning it on without a memory card? Just to eliminate your ML config from being the issue.

Long story short... I opened up the camera to replace the PCB. Immediately I noticed the power switch "ON/OFF/~" was disengaged from the switching mechanism. It seems to fall off if turned "OFF" with too much force. I now leave the switch in the "Locked" position all the time; to turn off the camera safely, just open the CF door and remove battery. The camera has worked fine since... now to get rid of the PCB that I never used...