Panasonic Quasar Omnivision PV-V4021-K, Service Manual

Page: 21 / 146

Fig. 9
4. Rewind the tape into the cassette by turning the Center Clutch Unit
counterclockwise.
5. Eject the cassette by ap10.0 V DC Power Supply again.
5.1.11. BLACK SCREWS ON THE CHASSIS
Black Screws are used on the Mechanism Chassis to identify screws that require adjustment.
5.1.12. HOW TO RESET ALL VCR MEMORY FUNCTIONS
To reset (clear) the select language, channel auto set and set clock functions to their initial power on
condition (power on, no cassette inserted), hold down the PLAY and CH UP buttons on the unit
together for more than 5 seconds.
Power will shut off.
5.1.13. HOW TO CONFIRM AUTO CLOCK SET FEATURE
1. Connect an RF cable from the output of one unit to the input of the
test unit.
2. Select corresponding RF channels.
3. Playback a recording of P.B.S. channel including clock set data and
confirm this feature.
5.1.14. VARIABLE VOLTAGE ISOLATION TRANSFORMER
An Isolation Transformer should always be used during the servicing of VCR whose chassis is not
isolated from the AC power line. Use a transformer of adequate power rating as this protects the
technician from accidents resulting in personal injury from electrical shocks. It will also protect VCR
from being damaged by accidental shorting that may occur during servicing.
Also, when troubleshooting the above type of Power Supply Circuit, a variable isolation transformer is
required in order to increase the input voltage slowly.
5.1.15. SPECIAL NOTE
All integrated circuits and many other semiconductor devices are electrostatically sensitive and
21