The Service Manual for the Kenwood KR-V55R provided by owner-manuals.com was as described/advertised. The contents provided the necessary information to effect a diagnosis of the unit. The schematics above all else was instrumental in tracing the the signal flow from component to component.
I bought the service-manual of the sony ICB-1020(an old transmitter-receiver) at "www.Owners-Manual.com", I found the service-manual for a fairly cheap price(in comparison with other sellers). I filled in some questions, payed the order with Ideal, and within 24 hours I had my service manual. I was very happy:In no time I had my service-manual and everything, but literally everything was noted down in the manual; the electronic scheme, the parts list, etcetera.
A very practical, reference-document.