iFixit - Answers With Device "Canon EOS 5D Mark II"

Canon EOS 5D Mark II: How the fix err01

Fri, 16 Jan 2026 12:29:09 -0700

I have cleaned the lens contacts even after doing so the lens is not working in auto mode and the other lens is still working!

⟐ Commented January 16, 2026 at 12:29 MST

Canon EOS 5D Mark II: How to fix error 06

Tue, 30 Dec 2025 02:32:32 -0700

self-cleaning sensor unit malfunction

⟐ Commented December 30, 2025 at 2:32 MST

Canon EOS 5D Mark II: USB port is damaged.

Sat, 06 Sep 2025 12:06:06 -0700

Hi My USB connection on the Camera doesn't work anymore. Can you fix it and how much does it cost? Also do you have a replacement cap for the Terminal System connection on the bottom plate of the camera?

⟐ Commented September 06, 2025 at 12:06 MST

Canon EOS 5D Mark II: Replacing the motherboard and need some instructions.

Fri, 07 Mar 2025 17:42:03 -0700

I don't know what I'm doing but I took apart my Canon 5d after it's been acting wonky and it looks like one of the little black things on the motherboard is corroded. I found a motherboard for $190 but no instructions anywhere on how to replace it. I was also told that Canon may have to "set up" the motherboard after I change it out but I don't know what that means. Can anyone enlighten me?

The way it acts wonky is after I've used it for a while, the select button won't work or only works when I move it in certain directions and the auto exposure lock will come on randomly and won't turn off on its own or when I take the battery out. And I've already done a hard reset.

⟐ Commented March 07, 2025 at 17:42 MST

Canon EOS 5D Mark II: Canon 5D Mark ii Button Fix

Mon, 07 Oct 2024 16:22:54 -0700

How Can I access live mode on my Canon 5D mark ii if the live button and menu button is not working?.

Is there a computer software that can help me to reassign button to other button like AF Button or Set Button

⟐ Answer unaccepted October 07, 2024 at 16:22 MST

Canon EOS 5D Mark II: Canon 5d mark ii constantly flashing "RED" busy light. No powerup.

Thu, 08 Feb 2024 18:32:50 -0700

Camera will not power on. As soon as a battery is installed busy light starts flashing and never stops

Canon EOS 5D Mark II: Rear lcd gets whiter and whiter or has horizontal lines.

Tue, 17 Oct 2023 20:35:16 -0700

I just got a faulty 5D mk2.
When I connect a good working rear panel (I also have a good 5D mk2), the lcd screen starts to get whiter and whiter (it doesn’t get brighter, just more white) so I have to turn it off in about 3 seconds.
I tried powering on about 3 times and each time the rear lcd either got whiter or had horizontal lines in different places.
It looked like it would destroy the lcd if I kept it powered on and the lcd that came with the camera only lights up all black (on both cameras) so it is broken.
But my good lcd still works perfectly on my good mk2.

Canon EOS 5D Mark II: How-to fix Error 80?

Sun, 15 Oct 2023 08:30:17 -0700

Greetings,

is there any way to fix the dreaded "Error 80" besides an expensive repair, nowadays ?

Thanks in advance

⟐ Answer edited October 15, 2023 at 8:30 MST

Canon EOS 5D Mark II: Where is the parts catalog?

Wed, 23 Aug 2023 19:47:54 -0700

There is a link on this page to a PDF file of what should be a parts catalog for this camera.

This does not link to anything.

Does any one have information on this, or maybe a copy of the file?

I tried checking the wayback machine at archive.org.

There was one capture from 2021, but it offers the same result as the link here.

I am trying to find the identity of the mainboard manufacturer for this camera.

Thanks for any and all help you can provide.

Best wishes in all your repair activities,

⟐ Answer accepted August 23, 2023 at 19:47 MST

Canon EOS 5D Mark II: How to repair card slot?

Thu, 10 Aug 2023 20:25:36 -0700

how to repair card slot ? My canon 5d mark ii Memory card slot has been dameged, how it will be repair ?

Canon EOS 5D Mark II: How to fix error 20

Thu, 20 Apr 2023 04:35:21 -0700

I have a 5d Mkii that keeps giving me a error 20. What is problem.

⟐ Answer edited April 20, 2023 at 4:35 MST

Canon EOS 5D Mark II: ALL batteries read as "empty" (flashing icon on top LCD).

Sat, 11 Mar 2023 16:38:12 -0700

I can't find anyone with a solid solution online.

Batteries that and confirmed to be good and charged will read as empty and my 5D mk II will not operate. Nothing on the rear LCD screen. Only a blinking empty battery on the top LCD. The top LCD comes to life and responds to settings changes (wheel to change aperture or shutter speed) for a second before becoming unresponsive and blinking the empty battery icon. I've replaced the internal "watch" battery.

⟐ Answer edited March 11, 2023 at 16:38 MST

Canon EOS 5D Mark II: Why won't my 5D Mk II turn on?

Fri, 24 Feb 2023 20:40:21 -0700

I flip the power switch to the on position but nothing happens. How can I turn my camera on?

⟐ Answered February 24, 2023 at 20:40 MST

Canon EOS 5D Mark II: How to fix error 30

Mon, 01 Aug 2022 22:20:21 -0700

how to repair my canon 5D mark ll (error 30)

⟐ Answer deleted August 01, 2022 at 22:20 MST

Canon EOS 5D Mark II: Focus constantly ahead, and micro adjustment is not enough

Fri, 06 May 2022 19:12:46 -0700

Hello! My 5D mark ii is not focusing on the object, but always a little ahead. I’ve tried micro adjustment, but even at -20 or +20 it makes no difference.

Cleaned contacts, air blow on focus sensor beneath mirror, changed lens

Interestingly on live view (contrast) it focus good, but by phase it is not working

Canon EOS 5D Mark II: How does one replace the lens contact bridge assembly?

Fri, 28 Jan 2022 00:04:06 -0700

The camera body is failing to communicate manual aperture settings to any lens and cleaning the contacts no longer works: what tools are required and what is the procedure for replacing the lens contact bridge assembly?

Canon EOS 5D Mark II: Nothing turns on except top screen

Wed, 28 Jul 2021 11:19:52 -0700

I’m having a weird issue with my Canon 5D Mark II. It’s like the camera is stuck in a mode that doesn’t allow me to take pictures. Only the top screen is on and seems to be displaying information normally. Any buttons connected to the main screen are unresponsive, the main screen is off. The battery is charged, I tried taking it out, taking the memory out, nothing has helped so far. I’d be grateful for any advice.

Canon EOS 5D Mark II: Error 30 no photo

Fri, 20 Nov 2020 07:51:47 -0700

Changed both batteries have a new card tried three. shutter sound ok cleaned all terminals. still get Err30 takes a couple of shots before err 30 then I can keep shooting through the error BUT have nothing recorded on mem card ? Canon 5DII.

Canon EOS 5D Mark II: false shutter count reading

Sat, 11 Jul 2020 22:39:18 -0700

My canon 5dmk2 is now reading a shutter count of over 4 million actuations? - it was previously around 50,000 last year, I believe it may be an issue with the electronics?

Canon EOS 5D Mark II: Camera stuck in permanent 'auto' mode

Thu, 28 May 2020 11:53:47 -0700

No matter what setting my camera is dialed too (M, Av, Tv, etc...) it operates as if it's in 'auto' mode. I can appear to adjust ISO, F-stop, etc... but nothing changes. The camera makes all the lighting choices on it's own. Any ideas on how to fix this or cost of fixing this issue?

Thanks!

⟐ Commented May 28, 2020 at 11:53 MST