GE Vivid i n - Page 364

GE HEALTHCARE
DIRECTION FQ091013, REVISION 1 VIVID I N AND VIVID Q N SERVICE MANUAL
7-12 Section 7-2 - Diagnostics
7-2-4-2-3 TR32 Tests
• Beamformer Tests
- TR32 BF Digital Test
This is an internal test of the Beamformers. Each Beamformer generates an internal test
pattern (first on the TR32A board and then on the TR32B board). This test pattern is
generated through MLA0 and MLA1 to the RFI.
Therefore, in the first phase of the test, the Beamformer on the TR32A board generates a test
pattern signal (while TR32B generates pattern zero).
In the second phase of the test, the Beamformer on the TR32A board generates a test pattern
zero - while the BF on the TR32B board generates a test pattern signal.
Both the test patterns are summed and focused on the BF 32A and generated to the RFI
demodulator.
For test procedure instructions, see the TR32 BF Digital Test section, page 7-46.
- System BF Digital Test
In this test, both Beamformers are generating internal test patterns. The patterns from the
BF of the TR 32B board are summed and focused in the BF of the TR32A board. From here,
the pattern is generated through MLA0 and MLA1 to the RFI.
For test procedure instructions, see the System BF Digital Test section, page 7-49
-ADC Test
The ADC Test is used to check that 1st harmonic, 2nd harmonic, 3rd harmonic, and
background noise are within pre-defined limits.
In this test, a signal is generated from the RFI into the TR switches. For all 64 channels of the
system, each signal goes through the following: pre-amplification, filtering, analog-to-digital
conversion, and focusing. The test signal is at a frequency of 2 MHz.
For test procedure instructions, see the ADC Test section, page 7-52.
• Receive (RX) Tests
- RX Test
The RX Test is performed with no probe connected. This is used to check that the signal
values at the input to the TR32 board are as expected.
When performing the RX Test, test signals are generated from the RFI, and the results are
expected to be of fairly high amplitudes with no distortion of the frequency.
For test procedure instructions, see the RX Test section, page 7-57.
7-2-4-2-4 PM Tests
•ACW Test
- ACW IQ Symmetry Test
The ACW (analog CW test) is performed when CW problems are suspected. Checks the
symmetry of I and Q signals. Inputs a test signal shifted from the mixer frequency, then
calculates the RMS of the I and Q vectors and compares them. The RMS vectors should be
lower than the defined limits (shown on the report).
For test procedure instructions, see the ACW IQ Symmetry Test section, page 7-61.