On 07/19/2017 05:44 PM, Joel Rees wrote:
This is another aspect of "closed source" gratis technology that is often swept under the rug. It used to be, for instance, that a TV in the US had a full diagram of working parts in the back case, so that the TV could still be fixed even if the manufacturer suddenly wiped their books and disappeared.
Not at all true! As a sideline I was a TV serviceman in the 1960s. There usually was a drawing of the tube numbers and positions somewhere in the set--more usually on an inside surface of the wooden box. There certainly was no schematic diagram. However, it was almost always possible to obtain real service information including schematic diagrams of the circuits from a paid service, the name of which escapes me now. (The pages always included useless ones for record players and such that nobody ever heard of!) --doug--almost 80!