Rms Value - Sony XBR-55X900H Service Manual

2020/06/27 06:31:32 (GMT+09:00)
1-4. Caution About the Lithium Battery
1) Danger of explosion if battery is incorrectly replaced. Replace only
with the same or equivalent type.
2) Outer case broken battery should not contact to water.
1-5. Safety Check-Out
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
connections. Check the entire board surface for solder splashes and
bridges.
2)Check the inter board wiring to ensure that no wires are pinched or
contact high-wattage resistors.
3)Check all control knobs, shields, covers, ground straps and mounting
hardware have been replaced. Be absolutely certain you 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.
5) Look for parts which, though functioning show obvious signs of
deterioration. Point them out to the customer and recommend their
replacement.
6) Check the line cords for cracks and abrasion. Recommend the
replacement of any such line cord to the customer.
7) Check the antenna terminals, metal trim, metalized knobs, screws and
all other exposed metal parts for AC leakage. Check leakage test as
described next.
8. For safety reasons, repairing the Power board and/or Inverter board is
prohibited.
SECTION 1
S E C T I O N 1
S A F E T Y N O T E S
SECTION 2 SECTION 3
1-6. Leakage Test
(To protect electric shock when customer touch the terminal.)
Leakage current can be measured by V: Voltmeter or oscilloscope
(r.m.s. or peak reading)
Stabilized power supply instrument and isolated voltage transformer:
Use too much current capacity and isolated voltage transformer does
not need to use stabilized power supply equipment.
Specification of RMS volt meter: Input resistance > 1 Mohm, Input
capacitance < 200 pF, Frequency range: 15 Hz – 1MHz . Refer
Figure 2. Isolated type volt -meter (FLUKE 8921A etc *1)
*1 Not use FLUKE 8920A that connected to protective earth by diode
# Leakage current of measurement instrument is less than 10μArms
when under test equipment AC plug is opened
# Set up the following condition and turn on the set. Applied voltage:
Nominal input voltage (Description on Nameplate)
# Measure the leakage current between one phase conductor and
neutral for terminal A and terminal B.
Read rms value, and then calculate to peak value PEAK VALUE =√2

RMS VALUE

Comply with the following requirement
Class II equipment (2-pin plug): for each terminal, the worst value
of measurement must not exceed AC 350uA peak).
Note: including AC adaptor, AC adaptor/DC operated unit
combination
SECTION 4 SECTION 5
Figure 2 – Measuring network
for Leakage Current
SECTION 6
11
SYS SET