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 55 (click to view)
3. Y/C CIRCUIT (4) When the Video signal doesn�t appear on the screen in REC Mode,
NO
Is the EE signal normal? YES Is 5V applied to the IC301 Pins 16, 40, 55, 58, 87? YES Does PB Mdoe operate normally? YES Does the RF signal appear at the IC301 Pin 12?
Check EE Mode.
NO
Check the line of the 5.2V Line.(Power Circuit)
NO
Check PB Mode.
NO
Is the REC �H� signal (about 4V) applied to the IC 301 Pin 30? YES
NO
Check the System of REC �H�. (the IC501 Pin 79 / the D301)
YES
Check REC Luminance Pass & Color Pass.
YES
Replace the IC301.
Does the REC RF signal appear at the IC301 Pin 90? YES Check the Drum & Drum Connector