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 19 (click to view)
First setup panel
Function Shows the battery level.
Turns the clock display on or off and lets you set 12 or 24h time display. Sets the clock. Sets the day. Sets how long the touch screen and the backlight of the touch screen stay on. Sets how long the backlight of the buttons stays on. Adjusts the brightness of the touch screen in 4 levels. Level 3 is the default brightness level.
Tap the clock repeatedly.
Tap the time button and use the action buttons . Tap the day button and use the action buttons . Tap the LCD button and use the action buttons . Tap the Button Light button and use the action buttons
Tap the Brightness button and use the action buttons .
When you set the brightness level above the default level (3), battery life time will be reduced. When you set the brightness level below the default level (3), battery life time will be prolonged.