Section 3 Safety Related Adjustment; B Voltage Check - Sony TRINITRON PVM-14L1 Service Manual

Section 3
Safety Related Adjustment
This section explains the adjustment procedure when
safety related component(s) is replaced. Perform the
following adjustment when the safety related component(s)
is replaced.
[Preparation]
Equipment Required
* VG (programmable video signal generator)
VG-854 or equivalent
* DC power supply
* Digital VOM
Advantest TR6845 or equivalent
* Slide induction transformer
Start the following adjustments after 5 minutes have
passed after the main power is turned on.
When the parts (with a ld mark on the circuit diagram)
shown below are replaced, confirm the matters described
in items 3-1 and 3-2 shown below.
A board
ld ..... C101, C102, D102, D103, D312, D314, Q102,
Q314, Q315, Q316, Q317, R101, R107, R108,
R110, R311, R315, R316, R317, R318, T501 (FBT)
3-1. +B Voltage Check
1. Supply the power source voltage of 127 to 130 Vac to
the set and turn ON the power.
2. Input the 480/601 all black signal, and adjust the
BRIGHT and CONTRAST knobs on the front panel to
MIN.
3. Check that the +B voltage is 115.0 to 119.0 Voc.
+B voltage measurement point
For 14-inch receiver :
Between T502 FBT pin-4 on A board and GND.
For 20-inch receiver :
Between T502 FBT pin-2 on A board and GND.
PVM-14L1/14L1MDE/20L1
SSM-14L1/20L1
3-2. Protection Circuit Confirmation
3-2-1. HV Protector Circuit Confirmation
2. Input the 480/60I all black signal, and adjust the
BRIGHT and CONTRAST knobs on the front panel to
MIN.
3. Confirm that the voltage between the D103 cathode
(TP502) and GND on the A board satisfies the standard
value.
Standard value : 19.5 Vpc or more (14 inch)
23.5 Voc or more (20 inch)
4. Apply the following voltage between the D103
cathode and GND on the A board, and confirm that the
protector circuit is not activated.
23.1 to 23.5 Voc (14 inch)
28.1 to 28.5 Vpc (20 inch)
5. Apply the following voltage between the cathode
(TP502) and GND of D103 on the A board, and
confirm that the protector circuit is activated and raster
disappears.
25.3 to 25.5 Voc (14 inch)
30.3 to 30.5 Voc (20 inch)
3-1