Voltage Measurements - Hitachi VTMX900ECT Manuel D'entretien

2. How to install the FLAT PACK IC
a. Use unsoldering braid to remove the solder from the foil of each
pin of the Flat Pack lC on the P.C.B. in order to install the
replacement Flat Pack IC more easily.
b. The "•" mark on the Flat Pack IC indicates pin 1.
Make sure this mark matches the 1 on the P.C.B. when positioning
for installation. Then pre-solder the four corners of the Flat Pack IC.
(see Fig. 2-9).
EXAMPLE
Pin 1 on FLAT PACK IC is marked by a "•".
Fig. 2-9
Soldering iron
C.B.A.
Fig. 2-10
c. Solder all pins of the Flat Pack IC. Make sure that none of the
pins have solder bridges between pins on the Flat Pack IC.
Note
All integrated circuits and many other semiconductor devices are
electrostatically sensitive and therefore require the special
handling techniques described in the "SAFETY INSTRUCTIONS"
section of this manual.
Presolder
FLAT PACK
IC

Voltage measurements

Color bar signal in SP REC and PB modes.
Note:
Voltage indications for the REC. and PB mode on the schematic
diagrams are shown below:
PLAY mode
REC. mode
Fig. 2-11
How to read wave forms
1 Connecting point
2 Amplitude
3 Time base
4 Operating mode of the VCR
2
1
Fig. 2-12
Voltage indication of Zener diodes
The Zener voltage of Zener diodes is indicated as such on
schematic diagrams:
Example:
BZX79C20............Zener voltage: 20 Volts
2-3
REC. and PLAY mode
(Identical voltages for
both modes).
4
3
GB