Turns out this was not the manual i was looking for. The concertmate 670 keyboard i have is a "Realistic" model made for Radio Shack and none of the diagrams on the owners manual i received matches up. HOWEVER, I must say the service Owners Manual provides was fast and efficient by being available online. The manual was in good readable condition and easily downloaded.
Thank´s for your help, I already recived these manual from you
Text excerpt from page 18 (click to view)
Installiation
procedure
C. Slide the chassis out of the cabinet.
1. Remove the front panel. Remove tape (if any). Lift panel and take it off the cabinet.
2. Remove the shipping brackets (2). Remove the cabinet ground screw (1) and disconnect the green and yellow grounding wire.
5. Install the drain plug and drain cup (accessory parts) to rear of cabinet. Slide drain cup down into rear support between grooves in cup. NOTE: Attach drain plug and drain cup assemblies and attach hose before sliding unit into cabinet.