Kenwood NXR-1800 Service Manual page 92

● Checking power supply
voltage (Fourth)
Checking voltage
VDD_MPU TL3
1.15V_SMPS2 TL4
1.06V_SMPS3 TL5
VSDMMC TL6
1.8V_LDO2 TL7
V1_8D TL8
1.8V_LDO3 TL9
V3_3USB TL10
V1_8PLL TL11
VDDS_DDR TL12
● Checking the clock
Checking the clock
MAIN_CLK TL16
CLKIN_20M_TO_PLD TL901
● Checking the MPU/DSP reset
and POWERGOOD signal
Checking the signal
PMIC_RESET_OUT R103
RESETN R114
PMIC_POWERGOOD IC7 (pin 4)
● Checking the SHLT signal
Checking the signal
SHLT R206
● Checking the OLED
control (First)
Check the FPC for OLED is inserted correctly and it is
not damaged.
● Checking the OLED
control (Second)
If nothing is displayed on the OLED
Checking the signal
DISPLAY_ON R661
DISPLAY_CTRL_ON R637
DISPLAY_RSTn R633
Checking the communication
waveform
DISPLAY_CS R618
DISPLAY_CMDn R619
DISPLAY_CLK_SCL R644
DISPLAY_MOSI_SDA R645
If two or more progress bars are not lit even though they
are displayed on the OLED, proceed to "Checking the
OLED control (Third)".
1-92 (No.RA094<Rev.002>)
Pass
Normal voltage
0.85 ~ 1.25V
1.11 ~ 1.2V
1.02 ~ 1.16V
3.3V
1.8V
1.8V
1.8V
3.3V
1.8V
1.5V
Pass
Frequency
20MHz (1.8V)
20MHz (3.3V)
Pass
Normal voltage
3.3V
3.3V
3.3V
Pass
Normal voltage
It changes from Low to High
(3.3V) within 1 minute after
the power is turned on.
Pass
Pass
3.3V
3.3V
3.3V
Normal voltage
Amplitude 3.3V
Amplitude 3.3V
Amplitude 3.3V
Amplitude 3.3V
Pass
Fail When all power supply voltage outputs are 0V, check the
voltage of R22 on the IC3 (pin 1, /RESET) line.
3.3V: This voltage is normal. IC1 may be broken.
0V: This voltage is abnormal. Check the following.
Check the voltage of R21 on the IC3 (pin 3, / MR) line.
3.3V: This voltage is normal. The area around IC3 may
be broken.
0V: FPGA may be broken.
When the power supply voltage output other than
VDDS_DDR is an abnormal value individually, IC1 or
MPU/DSP may be broken.
When the power supply voltage of VDDS_DDR is an
abnormal value, one of IC1, MPU/DSP or DDR3 may
be broken.
Fail
The BGA parts are not broken.
Fail
The BGA parts are not broken.
Fail
The BGA parts may be broken.
Fail
The BGA parts are not broken.
Fail
The FPGA may be broken.