EOS-1d Mk3 Mirror stays up error

[SaxonTony]

I am sure this must have been discussed before.

I have had my Mk3 from new around 2009 and it has not had much use and is still in mint unmarked condition.

However after about 3 shots the mirror stays up and i have to switch it off for it to go back down and then switch on again to use, until it stays up again.

I have used it like this for years but no I want to fix it so does anyone know what I need to do to correct it!

its 559799

[jrhoffman75]

1. If the camera was saving date and time the button cell was still working. That’s its only function. 
2. You said it’s been going on for years, so it’s probably not due to the battery. 
3. E99 is not a discrete error code. When searching for a repair shop be sure to check if they are aware of the original 1D Mark III problem. 

[ebiggs1]

The new battery(s) and complete reset are basically all the average person can do. If none of these simple tasks help then the camera truly needs service by a qualified repair shop.

[ebiggs1]

"When my main battery is charged up 3 green lights on the charger and I press calibrate..."

The charger discharges the main battery before it can do the recalibrate which is only mildly successful. It is best done when you put an already discharged battery on the charger.

[ebiggs1]

If error 99 only happens with one lens it can mean the lens is faulty. If it happens with any and all lenses then the camera is faulty. 

[SaxonTony]

I have updates- I was using my 24-105 F4L so tried my 85mm F1.8 - still got the error - but I have read the canon page on it which say I dont need to switch off or remove the battery - just press the shutter button half way - and that works - so Im happy to carry on using it that way. 

[ebiggs1]

"I found it and replaced it with a new duracell 2025, I waited an hour between taking the original battery out and putting the new one in."

If you left the button battery and main battery out for an hour you probably did complete a full reset. Besides  date/time the button battery saves your settings. Actually it is better called a 'keep alive' battery as it saves nothing itself.