A nice example of satellites that have no effectors whatsoever are the two Laser Geodynamics Satellites (LAGEOS 1 and 2)Laser Geodynamics Satellites (LAGEOS 1 and 2). Neither has an onboard computer. Neither has any effectors. Neither has any attitude control mechanisms.
< Source: NASA, via wikipedia. This image is public domain.
The LAGEOS satellites are very simple vehicles that orbit well above the atmosphere. They are solid spheres made of a dense material but are covered with retroreflectors. The retroreflectors enable ground-based observers to ping those satellites with lasers, hence the name. The LAGEOS satellites are used to investigate the Earth's rotation and to investigate aspects of general relativity.