Inspiron 7500 Keycap problems

I have an old P-3 500MHz I-7500 that my wife uses for eMail, and with the slow old IBM drive replaced by a Hitachi 7200 RPM 40GB it works pretty well for her, and she likes the big 1280x1024 screen. Lately she's complained that the "R" key doesn't always work. I found the keycap loose, with the right side of it is pretty much adrift, and can't figure out how to re-fasten it. Ids appreciate any advice and/or web site references on how they're fastened down, how to re-connect them (if possible), and/or any sources for surplus keyboards and instructions for R&Ring same.

 

It should just pop back in, or have a little hook type fastener that it attatches to, if not Ebay always has surplus keyboards for many laptop models and are usually reasonably priced.

 

I had the "5" key pop off of my Dell I9300 not too long ago. I tried for a long time to reattach it before discovering a couple of little plastic prongs had snapped off. Basically, if that happens (which is very likely if the whole key assembly is lose rather than just the keycap), a new keyboard or "grin and bear it" are your only options.

 

Thanks to both of you. I found the little pantograph like plastic spring assembly under the cap was loose from the cap, as well as disconnected from the small metal loops surrounding the rubbery switch cover. And indeed, almost impossible to put back in place, or to tell if some very small plastic tab was broken. I offered her a nice Northgate Ultra keyboard (THE BEST, hands down) but she doesn't want to give up the extra desk space. So I found one on e-Bay Express for $2.00 - plus $12 for FedEx; still, not bad. Also found a site with Dell instructions on which screws to remove and cautions on loosening the ZIF connector, so now to wait for the part.