2. Select corresponding RF channels.
3. Playback a recording of P.B.S. channel including clock set data
and confirm this feature.
5.1.16. VARIABLE VOLTAGE ISOLATION TRANSFORMER
An Isolation Transformer should always be used during the servicing of Combination 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 Combination 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.
5.1.17. SPECIAL NOTE
All integrated circuits and many other semiconductor devices are electrostatically sensitive and
therefore require the special handling techniques described under the
"ELECTROSTATICALLY SENSITIVE (ES) DEVICES" section of this service manual.
5.1.18. REPLACEMENT PROCEDURE FOR LEADLESS (CHIP) COMPONENTS
The following procedures are recommended for the replacement of the leadless components
used in this unit.
1. Preparation for replacement
A. Soldering Iron
Use a pencil-type soldering iron that uses less than 30 watts.
B. Solder
Eutectic Solder (Tin 63 %, Lead 37 %) is recommended.
C. Soldering time
Do not apply heat for more than 4 seconds.
D. Preheating
Leadless capacitor must be preheated before installation. - (266 °
F ~ 302 °F)
(130 °C ~150 °C) for about 2 minutes.
Note:
A. Leadless components must not be reused after removal.
B. Excessive mechanical stress and rubbing of the component
electrode must be avoided.
2. Removing the leadless component
Grasp the leadless component body with tweezers and alternately
apply heat to both electrodes. When the solder on both electrodes
is melted, remove the leadless component with a twisting motion.
Note:
21
To Next Page
Loading...
