I have a Kenwood cd changer car tape there is no audio, i have changed the audio ic but there is stil no audio, i have also sent it to kenwood agents and they failed to repair it any suggestion.
GUYS CAN ANYONE HELP WITH SCHEMATICS
You say you've already replaced the audio output ic?
Then, you sent it to an authorized Kenwood service and they failed to repair it?
What did they say? If they could not find a problem, check your speaker/wiring.
If your audio output ic was shorted, it's possible that the line that provides the vcc for the ic has an open resistor, and no voltage is getting to the new ic.
What I've done in the past when I had trouble finding a schematic was to cross the audio output ic to a ECG or NTE equivilent, and find out what pin provides the vcc of that device, as it will be the same as the original. From there, you can trace it back by following the foil pattern. If that's the issue, it'll be a low value resistor, most likely, that's open.
The pin out info from the cross is quite useful. If it is getting voltage, you can check to ensure that it's getting input, etc.
This at least, gives you something to try.