Emerson EWV401B Service Manual page 32

Main CBA Bottom View
CAUTION !
Fixed voltage power supply circuit is used in this unit.
If Main Fuse (F001) is blown, check to see that all components in the power supply
circuit are not defective before you connect the AC plug to the AC power supply.
Otherwise it may cause some components in the power supply circuit to fail.
1-9-20
CAUTION
FOR CONTINUED PROTECTION AGAINST FIRE HAZARD,
F REPLACE ONLY WITH THE SAME TYPE FUSE.
ATTENTION : POUR UNE PROTECTION CONTINUE LES RISQES
D'INCELE N'UTILISER QUE DES FUSIBLE DE MEMO TYPE.
A V
RISK OF FIRE-REPLACE FUSE AS MARKED.
"This symbol means fast operating fuse."
"Ce symbole reprèsente un fusible à fusion rapide."
1-9-21
BECAUSE A HOT CHASSIS GROUND IS PRESENT IN THE POWER
SUPPLY CIRCUIT , AN ISOLATION TRANSFORMER MUST BE USED.
ALSO , IN ORDER TO HAVE THE ABILITY TO INCREASE THE INPUT
SLOWLY , WHEN TROUBLESHOOTING THIS TYPE POWER SUPPLY
CIRCUIT , A VARIABLE ISOLATION TRANSFORMER IS REQUIRED.
NOTE :
The voltage for parts in hot circuit is measured using
hot GND as a common terminal.
NOTE :
Either BHB400F01016, BHB400F01017
is used for the Main CBA in this S/M.
Note:
The Tuner Unit ( TU701 ) is either type A or type B.
Wave Form will be different. It depends on the type of
tuner used on the unit you are servicing.
Main CBA
Ref.No Position
ICS
IC001 F-2
IC301 C-3
TYPEA TYPEB
IC451 B-3
IC501 D-1
TRANSISTORS
WF8 WF8 WF8 WF8
Q001 F-2
Q002 F-2
Q031 F-2
Q052 F-1
WF8 WF9 WF8 WF9
Q055 E-1
Q056 E-1
Q065 E-1
WF10 WF8 WF10 WF8 Q301 C-2
Q302 C-2
WF11 WF8 WF11 WF8
Q303 C-2
Q391 A-2
Q421 E-3
Q422 F-2
Q425 E-2
WF13 WF8
Q426 D-3
WF14 WF8
Q501 B-1
Q503 A-3
Q504 F-3
Q506 D-2
CONNECTORS
CL253 C-3
WF13 WF8
CL501 B-3
CL502 E-2
WF14 WF8
CL504 E-4
CL507 F-1
VARIABLE RESISTORS
VR501 A-1
TEST POINTS
TP301 A-2
TP302 A-1
TP303 A-1
TP502 F-1
TP505 A-1
TP506 F-1
TP751 A-2
TP752 A-3
TP753 A-3
TP754 A-3
BHB400F01016-A
1-9-22