FLY DS 110, Service Manual

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DS 110 Service menu
Boot process:
The normal boot is to press boot key which is that the PWRKEY is being dragged down.
Once the boot key is pressed, all LDO are open except VSIM. After VCORE
opening RESET timer and timer out, RESET is being pitched up to start the digital
baseband chip, that is, UMT6223D starts to run and roll polling its ROWX pin, pitch up its
PWRONIN pin, then you can release the boot key. This is the initial boot process.
3.4 Audio Frequency
The sound quality performs more pleasant on account of audio processing integrated in
UMT6223D
3.4.1 Speaker loop
3.4.2 MIC loop
Check basic bias voltage signal of MICBIASP and MICBIASN and the language signal of
MIC itself when the MIC is good but no response of LOOP MIC in test.
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