Sony CPD-G420 (serv.man3) Service Manual ▷ View online
CPD-G420(E)
2
LEAKAGE TEST
The AC leakage from any exposed metal part to earth ground and from all
exposed metal parts to any exposed metal part having a return to chassis,
must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA WT-
exposed metal parts to any exposed metal part having a return to chassis,
must not exceed 0.5 mA (500 microamperes).
Leakage current can be measured by any one of three methods.
1. A commercial leakage tester, such as the Simpson 229 or RCA WT-
540A. Follow the manufacturers’ instructions to use these instruments.
2. A battery-operated AC milliammeter. The Data Precision 245 digital
multimeter is suitable for this job.
3. Measuring the voltage drop across a resistor by means of a VOM or
battery-operated AC voltmeter. The “limit” indication is 0.75 V, so
analog meters must have an accurate low-voltage scale. The Simpson 250
and Sanwa SH-63Trd are examples of a passive VOMs that are suitable.
Nearly all battery operated digital multimeters that have a 2 V AC range
are suitable. (See Fig. A)
analog meters must have an accurate low-voltage scale. The Simpson 250
and Sanwa SH-63Trd are examples of a passive VOMs that are suitable.
Nearly all battery operated digital multimeters that have a 2 V AC range
are suitable. (See Fig. A)
After correcting the original service problem, perform the following safety
checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly-soldered
checks before releasing the set to the customer:
1. Check the area of your repair for unsoldered or poorly-soldered
connections. Check the entire board surface for solder splashes and
bridges.
bridges.
2. Check the interboard wiring to ensure that no wires are “pinched” or
contact high-wattage resistors.
3. Check that all control knobs, shields, covers, ground straps, and
mounting hardware have been replaced. Be absolutely certain that you
have replaced all the insulators.
have replaced all the insulators.
4. Look for unauthorized replacement parts, particularly transistors, that
were installed during a previous repair. Point them out to the customer
and recommend their replacement.
and recommend their replacement.
5. Look for parts which, though functioning, show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
replacement.
6. Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7. Check the B+ and HV to see if they are specified values. Make sure your
instruments are accurate; be suspicious of your HV meter if sets always
have low HV.
have low HV.
8. Check the antenna terminals, metal trim, “metallized” knobs, screws, and
all other exposed metal parts for AC Leakage. Check leakage as
described below.
described below.
Fig. A. Using an AC voltmeter to check AC leakage.
1.5 k
Ω
0.15
µ
F
AC
Voltmeter
(0.75 V)
Voltmeter
(0.75 V)
To Exposed Metal
Parts on Set
Parts on Set
Earth Ground
SAFETY CHECK-OUT
CPD-G420(E)
3
WARNING!!
NEVER TURN ON THE POWER IN A CONDITION IN WHICH THE
DEGAUSS COIL HAS BEEN REMOVED.
DEGAUSS COIL HAS BEEN REMOVED.
SAFETY-RELATED COMPONENT WARNING!!
COMPONENTS IDENTIFIED BY SHADING AND MARK
¡
ON THE
SCHEMATIC DIAGRAMS, EXPLODED VIEWS AND IN THE
PARTS LIST ARE CRITICAL FOR SAFE OPERATION. REPLACE
THESE COMPONENTS WITH SONY PARTS WHOSE PART
NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN
SUPPLEMENTS PUBLISHED BY SONY. CIRCUIT ADJUST-
MENTS THAT ARE CRITICAL FOR SAFE OPERATION ARE
IDENTIFIED IN THIS MANUAL. FOLLOW THESE PROCEDURES
WHENEVER CRITICAL COMPONENTS ARE REPLACED OR IM-
PROPER OPERATION IS SUSPECTED.
PARTS LIST ARE CRITICAL FOR SAFE OPERATION. REPLACE
THESE COMPONENTS WITH SONY PARTS WHOSE PART
NUMBERS APPEAR AS SHOWN IN THIS MANUAL OR IN
SUPPLEMENTS PUBLISHED BY SONY. CIRCUIT ADJUST-
MENTS THAT ARE CRITICAL FOR SAFE OPERATION ARE
IDENTIFIED IN THIS MANUAL. FOLLOW THESE PROCEDURES
WHENEVER CRITICAL COMPONENTS ARE REPLACED OR IM-
PROPER OPERATION IS SUSPECTED.
CPD-G420(E)
4
POWER SAVING FUNCTION
This monitor meets the power-saving guidelines set by VESA,
E
NERGY
S
TAR, and NUTEK. If no signal is input to the
monitor from your computer, the monitor will automatically
reduce power consumption as shown below.
reduce power consumption as shown below.
*
Figures reflect power consumption when no USB compatible
peripherals are connected to the monitor.
peripherals are connected to the monitor.
** When your computer enters power saving mode, the input signal is
cut and NO SIGNAL appears on the screen before the monitor enters
active off mode. After a few seconds, the monitor enters power saving
mode.
*** “Deep sleep” is power saving mode defined by the Environmental
Protection Agency.
Power mode
Power
consumption
consumption
*
!
(power)
indicator
normal
operation
operation
≤
135 W (CPD-G520)
≤
130 W (CPD-G420)
green
active off**
(deep sleep)***
(deep sleep)***
≤
3 W
orange
power off
Approx. 0 W
off
CPD-G420(E)
5
DIAGNOSIS
Failre
+B failure
Horizontal / Vertical Deflection
failure, Thermal protector
failure, Thermal protector
ABL protector
HV failure
Aging / Self Test
Out of scan range
Power LED
Amber
→
Off
(0.5 sec)
(0.5 sec)
Amber
→
Off
(1.5 sec)
(0.5 sec)
Amber
→
Off
(0.5 sec)
(1.5 sec)
Amber
→
Off
→
Amber
→
Off
(0.25 sec)
(0.25 sec)
(0.25 sec)
(1.25 sec)
Amber
→
Off
→
Green
→
Off
(0.5 sec)
(0.5 sec)
(0.5 sec)
(0.5 sec)
Green (OSD indication)
Aging Mode (Video Aging) : During Power Save, press MENU button for longer than 2 second.
Self Test (OSD Color Bar)
: During Power Save, push up Control button for longer than 2 second.
Reliability Check Mode
: During Power Save, push down Control button for longer than 2 second.