Self Troubleshoot before proceed any further. 

Please include the test result when resorting for email support.

1.After connecting to wall outlet and pressing the power button, does the receiver red indicator light up?

2.Using fresh batteries for transmitters. After powering them on, do transmitter screens and both B & C indicators of receiver turn on and stay solid? 

3.If B & C indicators flash, does reset help?

4.If reset doesn't work, before reset, are all units off? During reset: does screen B blink and 596MHz appear (or screen C blink and 586MHz appear)?   

5.Is audio source hooked up to the R+L in jack, while output is connected through R+L/AUX out? 

4.Are all volume controls on receiver/speaker set to decent level?    

Q: How to reset the K038 dual wireless mics system?

A: You can find step-by-step tutorial on K038 problem-solving playlist: http://bit.ly/k038problemsolving

1. Turn off the power to receiver as well as transmitters B & C before you get started. 
2. Power on transmitter B and reset it by clicking the top button for 10 times. A flashing 605.000 channel number shows up if you reset transmitter B proper.   
3. The same goes for transmitter C. But what appears on transmitter is the flashing 584.000 channel.   
4. When they are still flashing, switch on receiver. Pay a bit attention here if its RF B & C lights will blink for 3 times before the last step.    
5. Click the top buttons of both transmitter B & C, resulting in pairing successfully.