For foreigners looking for Canon Camera Service Centres in Beijing, here are some locations.
Do call them before going down in case the service centres are closed or shifted.

their main line is 4006-222666

pls make sure you call before going down.

1. Dongcheng Canon Repair Centre
北京市东城区金宝街89号金宝大厦15层
Tel: 010-85139999/010-85139932
here’s a map to its location if you can read chinese

http://www.canon.com.cn/support/fastrepair/beijing_jinbao.html

2. Beijing International Convention Centre
- Canon Repair Centre
佳能照相机维修中心
Jia neng xiangji wei xiu zhong xin
北京北四环的北京国际会议中心的二层。
Wei yu Beijing bei si huan de Beijing guoji huiyi zhongxin de 2ceng.

Located on the North Fourth Ring Road in the Beijing International Convention Centre on the 2nd floor

3. Wudaokou Canon Repair Centre
北京市海淀区北四环西路9号保福寺桥东北角银谷大厦1层店铺
Tel: 010 62800300/62800301

there’s a new canon showroom at Sanlitun SOHO (just opposite Sanlitun Village)
Building 2, Ground floor, room 2101
I’m not sure if they provide camera repair or servicing at that location but it’s worth checking out if you are in that neighborhood.