JVC AV-T2122 Service Manual page 23

AV-T2122AR
2-12 No.51866
AV-T2122
/AR
n NOTE ON USING CIRCUIT DIAGRAMS
1.SAFETY
The components identified by the    symbol and shading are
critical for safety. For continued safety replace safety critical
components only with manufactures recommended parts.
2.SPECIFIED VOLTAGE AND WAVEFORM VALUES
The voltage and waveform values have been measured under the
following conditions.
(1)Input signal
(2)Setting positions of
each knob/button and
variable resistor
(3)Internal resistance of tester
(4)Oscilloscope sweeping time
(5)Voltage values
– S ince the voltage values of signal circuit vary to some extent
according to adjustments, use them as reference values.
3.INDICATION OF PARTS SYMBOL [EXAMPLE]
In the PW board :R1209¨R209
œ
4.INDICATIONS ON THE CIRCUIT DIAGRAM
(1)Resistors
œResistance value
No unit :[¶]
K :[K¶]
M :[M¶]
œRated allowable power
No indication :1/10 [W]
Others :As specified
œType
No indication :Carbon resistor
OMR :Oxide metal film resistor
MFR :Metal film resistor
MPR :Metal plate resistor
UNFR :Uninflammable resistor
FR :Fusible resistor
*Composition resistor 1/2 [W] is specified as 1/2S or Comp.
(2)Capacitors
œCapacitance value
1 or higher :[pF]
less than 1 :[µF]
œWithstand voltage
No indication :DC50[V]
Others :DC withstand voltage [V]
AC indicated :AC withstand voltage [V]
*Electrolytic Capacitors
47/50[Example]:Capacitance value [µF]/withstand voltage[V]
VP0109
DP6051
STANDARD CIRCUIT DIAGRAM
œType
No indication :Ceramic capacitor
MY :Mylar capacitor
MM :Metalized mylar capacitor
PP :Polypropylene capacitor
MPP :Metalized polypropylene capacitor
MF :Metalized film capacitor
TF :Thin film capacitor
BP :Bipolar electrolytic capacitor
TAN :Tantalum capacitor
: Color bar signal
(3)Coils
No unit :[µH]
Others :As specified
(4)Power Supply
:Original setting position
:B1
when shipped
:DC 20k¶/V
:9V
:H Ë 20µS/div
*Respective voltage values are indicated
:V Ë 5mS/div
(5)Test point
:Others Ë Sweeping time is
:Test point
specified
(6)Connecting method
:All DC voltage values
:Connector
:Receptacle
(7)Ground symbol

:LIVE side ground

:ISOLATED(NEUTRAL) side ground
:EARTH ground
:DIGITAL ground
5.NOTE FOR REPAIRING SERVICE
This model’s power circuit is partly different in the GND. The
difference of the GND is shown by the LIVE : () side GND and the
ISOLATED(NEUTRAL) : () side GND. Therefore, care must be
taken for the following points.
(1)Do not touch the LIVE side GND or the LIVE side GND and the
ISOLATED(NEUTRAL) side GND simultaneously. If the above
caution is not respected, an electric shock may be caused.
Therefore, make sure that the power cord is surely removed from
the receptacle when, for example, the chassis is pulled out.
(2)Do not short between
ISOLATED(NEUTRAL) side GND or never measure with a
measuring apparatus ( oscilloscope, etc.) the LIVE side GND and
ISOLATED(NEUTRAL) side GND at the same time. If the above
precaution is not respected , a fuse or any parts will be broken.
ž Since the circuit diagram is a standard one, the circuit and
circuit constants may be subject to change for improvement
without any notice.
ž NOTE
Due improvement in performance, some part numbers show
in the circuit diagram may not agree with those indicated in
the part list.
When ordering parts, please use the numbers that appear in
the Parts List.
AV-T2122AR
:B2(12V)
:5V
:Only test point display
:Wrapping or soldering
the LIVE side GND and
Sept. 2001 No. 51866