Sony WEGA KV27FV15 Training Manual page 28

Flyback Secondary Voltages Distribution
The following voltages are scan derived. This means that some windings
of the flyback transformer have their signals rectified to create additional
power supply lines:
200 Volts C Board IC1701 CRT Amp
+12 Volts A Board IC501 Pin Control, IC561 V Out
-15 Volts IC501 Pin Control, IC561 V Out, Q511 Pin Drive, WA Board
IC961 N/S Amp
The scan-derived supplies are developed when the output from Q502 H
Out is input to T503 Flyback Transformer. This signal is used to create
the boosted B+ (+200) on the primary side and the +12 and –15 volts on
the secondary side. The signal from T503/4 is sent through R553 and
rectified by D534. This voltage is output from CN503/5 on the A board to
CN503 on the C board. This voltage is used to supply IC1761 CRT Amp
on the C board. This connector can be disconnected to check to see if the
problem is with IC1761 CRT Amp.
FROM
Q502/C
H OUT
PART OF
T503
FLYBACK
1
4
B+
2
5
6
23
The +12 volt line is derived from the signal at T503/9. It is sent through
R537 and rectified by D531. In the event that a short occurs on this line,
R537 may open. Since the vertical output is supplied by this line, R537
should always be checked if a vertical output failure is suspected.
The -15 volt line is derived from the signal at T503/7. It is sent through
R536 and rectified by D530. In the event that a short occurs on this line,
R536 may open. Since the vertical output is supplied by this line, R536
should always be checked if a vertical output failure is suspected.
In addition to the scan derived supply voltages, T503 Flyback Transformer
also develops heater voltage from T503/5. T503 also develops high volt-
age, focus voltage and ABL.
9 +12V
To A Board IC501 Pin Control, IC561 V Out
R537 D531
8
To IC501 Pin Control, IC561 V Out, Q511 Pin Drive, WA
7
-15V
Board, IC961 N/S Amp
R536 D530
TO H
PROTECT
D534
R553
C541 R538
SCAN DERIVED SUPPLIES
1
TO CN503
C BOARD
5
CN503
1/4/00
9CTV26