Service manuals for the P3502C oscilloscope

Does anyone have copies of the Service manuals for the P3502C? I have a batch of these scopes at a community college that are not working correctly, and would like to try to repair them. Many show a false line signal and act as if the input is floating, or not connected, even when grounded.

There is a copy of user/service manual among other stuff;
http://zetaweb.org/web/manuals/

try this
**broken link removed**

harv