What if the replacement upper cylinder doesn work?
There are a number of possibilities and one of the more common particularly with generic replacements is, guess what? A defective replacement! When replacing the upper cylinder, the orientation and wiring must be exactly the same as the original. For many VCRs, this is automatic since the mounting is keyed and the wiring is via direct printed circuit board connections. However, there are also many where it is possible to screw up either the orientation or wiring or both: • For lack of color, erratic color, excessive video noise, and tracking problems double check its orientation. Accidentally replacing the head drum 180 degrees from its correct orientation will result in a variety of video quality problems. • Where individual wires are used rather than soldered connection to a printed circuit board from below, make sure you have attached the lower cylinder terminals to the proper heads. Some generic heads apparently do not have the identical layout. It may be necessary to visually trac
