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1. No raster (screen is not lit), no picture, no sound
Check main chip
pin 156 LED
control status.
Check main chip and
FLASH periphery.
Check NS01 pin 44 waveform
is sine wave or not.
Check NS01 crystal
oscillator circuit.
Note: If detect NS01 (main chip) pin 169 is of high level, you may remove RS14, detect VS01
emitter if first output high level after power on, then output low level continuously. If not, the reset
circuit may have problem. First detect if NS01 (main chip) pin 44 waveform is sine wave, if not,
check NS01 crystal oscillator circuit. When checking periphery of NS01, NS02 and NS05, check
relative component's welding, then use oscilloscope to detect the joint resistor pin between NS01
and NS05. If the waveform is not regular square-wave, that means either NS01 or NS05 work
abnormally and therefore cause address line and data line be in error. NS05 error probability is
greater. In addition, if joint resistor between NS01 and NS05 is in error, it will also cause no raster,
no picture and no sound.
Check if indicator
lights blue.
Yes
No
Check main chip
(NS01), FLASH
(NS02) power.
Abnormal
Check if main chip pin169
(reset receiving signal) is of
low level.
Yes
No
Yes
No raster,
no picture & sound
Check if indicator lights up.
Yes
No
Normal
Check circuit of
infrared sensor board.
No
Check NS01, confirm NS01
has reset correctly.
Check NS01, NS02, NS04,
NS05 and its periphery.
13
Check Standby _ 5V
Normal
Abnormal
Disconnect power
board and Data
process board, then
test Standby _ 5V
again.
Normal
Abnormal
Power board
exists
problem.
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