On Wed, Jan 1, 2025 at 11:22 AM, Hans Summers wrote:
QMX is the outstanding problem. We will find a solution to that too.?
The QMX boards could be tested with some sort of bed of nails test fixture that provided the appropriate test signals for IC403 couldn't they?
Use the CLK2 signal attenuated by R513 with a suitable level and phase shift, then the Rx Audio and Image tests should work.? That's enough to test most of the Rx side on an unpopulated board.
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Yeah like my QCX-mini test fixture:
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Yes, that's the sort of thing I was thinking of, not surprised you have already tried it..
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I understand that it's a lot of work to make but if 1 in 7 of the QMX kits fail because of the PCM1804 problem 100% testing seems essential.? I don't think it's reasonable to keep shipping QMXs untested if that level of failure can be expected, it isn't fair on your customers.
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Would a test rig that picked up the test signal from R518 and passed it through T401 to the inputs of IC403 work?? Your test harness would provide VCC and VDD and ground, that's 6 or 7 pins.? Run the Rx diagnostics through the USB connection.? This bypasses the LPFs and the BPFs but if they are needed they could be added to the test rig and a single band test done.? The alternative seems to be to connect each board manually using test clips, time consuming and error prone.
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Chris, G5CTH
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