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There are several steps we may need to do, but before we try and upgrade the software and firmware. lets try a simple fix first.
Start with the unit powered off. Then touch your finger on the lower right hand corner of the touchscreen and keep it there.
Then, while holding your finger on the lower right hand corner of the touchscreen. Turn on the unit.
It should ask you if you want to select all user data.. Choose yes. Once the reset completes test the device. Do you have sound back now?
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