Might be an idea to download the service manual, they do come in handy, tell you what order to take them apart and how to do it. Though I haven't looked at a Compaq manual, have used my Dell and my granddaughter's HP manuals, makes things a lot easier. Here's a link to the 1700 series manual at a blog, don't know if Compaq would still offer one at their site given the age of the machine. It's in .rar format, so needs to be unzipped. That's the WinRar file extension, but other unzip utilites will probably work, I just use winrar when I get that type of file.
http://netfree1.blogspot.com/2008/03...nd-repair.html
Could also be that something wasn't reconnected when you reassembled it.