High Voltage Stage (Ra-5A Chassis); Hv Power Supply Start Up (Board Level Repairs); Hv Block Description (Component Level Repairs) - Sony KD-34XBR2 Training Manual

HV Power Supply Start Up (Board level repairs)

As shown in Chart 21-1, the HV stage starts when enabled by three inputs.
1. +135Vdc D6104 / cathode (G Bd – Sec PS)
2. +12Vdc
3. H Drive
Once these three voltages are present, there is no reason the HV should not start unless the D board HV circuitry
is defective. See Testing for the procedure and location of the checkpoint connectors.
The HV stage can be tested for operation and level by measuring the sample of the HV at:
CN8016/pin 3 = 7.46Vdc. See Figure 21-2 for the schematic and " Testing" for connector locations.

HV Block Description (Component level repairs)

The HV Stage only has a few major blocks as shown in Figure 21-1.
G BD.
CN6106/
CN8013
3
+15V
+135V
9
+135V
+135V 10
CN3005/
CN8004
CN3007/
CN8006
10
H DRIVE
H DRIVE
IC3006/40

High Voltage Stage (RA-5A Chassis)

Chart 21-1- HV Stage Inputs (for Starting)
Name
12V Reg IC8004 / output (D Bd)
Video Process IC3006/pin 40
IC8004
12V REG.
7.46V
+135V
IC8008
Q8035
PWM
HV REG.
GEN.
Q8038
DRIVER
HV OUT
FIGURE 21-1 - RA-5 HV BLOCK
From
+12V
T8005
FBT
T8004
LOT
ABL
IC8006, 7
PROT.
95
21. RA-5A Chassis High Voltage Stage
Checkpoint
Q8035/ S (D Bd)
IC8008/1 (bottom) or
(CN8016/pin 1, 2)
CN8006/pin 10
CN8016
1
2
7.46V
3
HV DIST.
BLOCK
4
1
CN8022/
CN7304
C BD.
CRT
R
G
B
200V
TO VIDEO
OUTPUT
45TVP 1366 9/4/01