Canon issued a Product Advisory on the original EOS-5D camera that was announced in August 2005.
It is not regarding a new problem, but is a reminder that the after-sales service period (service reception period) for this product will end on September 30, 2015.
It involves a possible mirror detachment and repair will be free of charge, after almost 10 years. See the notes about the advisory below.
Canon Issues EOS 5D Classic Service Advisory
Please note that the after-sales service period (service reception period) for this product will end on September 30, 2015. The free repairs are also scheduled to end on the same day.
We have discovered that, in rare instances, the main mirror of some EOS 5D Digital SLR cameras may detach due to deterioration in the strength of the adhesive. Accordingly, we would like to convey the details and our service policy concerning this phenomenon.
We offer our sincerest apologies to those customers who have been inconvenienced by this issue. Canon always strives to provide the highest quality products to our customers and we will spare no effort in our quality management to make sure our customers can use our products with confidence. We hope our efforts will earn your understanding.
The main mirror of the camera detaches and images cannot be viewed through the viewfinder.
EOS 5D Digital SLR cameras whose main mirror has detached.
We will repair and reinforce the mirror portion of the affected products free of charge. If you own one of the affected products, please contact our Customer Support Center.
We appreciate your patience, and we offer our sincerest apologies to the customers using these products who have been inconvenienced by this issue.
via Canon USA