The Blu Dash 5.0 Dual SIM D410 was released September 3 2013. Repairing this device is relatively complex and requires tools that have to be purchased.
crwdns2893826:0crwdne2893826:0: Mud 14, 2015
No one can hear me talking but I can hear them
crwdns2893826:0crwdne2893826:0: Kho 14, 2015
it seems to be your MIC or PCM part is faulty. replace new MIC and check
Mic is located under the motor (Vibrator)
Here is the teardown guide.