GE LOGIQ E9 Service Manual page 255

GE
D 5573152-100, R
IRECTION
7-5-8-9 Analog CW (cont'd)
Name: Service Diagnostics / Analog CW / GRX ADC Digital LVDS
For the Analog-to-Digital Converter Digital Low-Voltage Differential Signaling test, the digital link from
the Doppler ADC and to the GFI board is verified. To verify signal integrity, the ADC is set up to
continuously transmit a predefined bit-pattern. Both I- and Q-data are acquired and each sample value
is tested. Port 0 on the PCA9554 I2C register on the GRX board is used to turn the ADC test pattern on/
off. The test signal generator on GFI is disabled for this test.
Are the probes connected? The test will run with probes connected to the scanner, but it is
recommended to disconnect all probes before running diagnostics.
Run Time: 00:05
1.) Verify the following tests pass:
-
-
If these tests pass, and the GRX ADC Digital LVDS test fails:
2.) Replace the CW GRX board.
Name: Service Diagnostics / Analog CW / GRX Mixer Phase Setup
This test utilizes a PCA9554 I2C register on the GRX board. All phase bits are set to one in the analog
Doppler setup data, before reading back from the I2C register and test bits 6 and 7 in the returned byte.
Next, all zeroes are sent to the analog Doppler, read back again and bits 6 and 7 appear in the returned
byte. The test passes if the bits of interest in the read back byte match the phase values that were setup.
Bit 6 and 7 are the last bits in the two shift register chains and if the correct value were read, the chains
must be intact. The test signal generator on GFI is disabled for this test.
Are the probes connected? The test will run with probes connected to the scanner, but it is
recommended to disconnect all probes before running diagnostics.
Run Time: 00:05
1.) Verify the following tests pass:
-
-
If these tests pass, and the GRX Mixer Phase Setup test fails:
2.) Replace the CW GRX board.
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EV
GFI Tests
Analog Receive Tests
GFI Tests
Analog Receive Tests
Chapter 7 Diagnostics/Troubleshooting
LOGIQ E9 S M
ERVICE ANUAL
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