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Echo Dot 3rd Gen Smart speaker Teardown

Published on Sunday 21 July 2019
Categories: Home Automation |

Amazon Echo Dot Rev 3 Teardown

In the summer prime sale at Amazon we purchased a third generation Amazon Echo Dot which is a small voice-controlled speaker using Amazon’s Alexa voice command service. Part Two of this post is on Echo Dot 3rd Gen Digging Deeper.

As this is the first Amazon echo dot device we have purchased, we decided to take it apart to see what you get for your £22.00.

In the Box

  • The echo dot
  • 240V UK power supply
  • Things to try leaflet
  • Setup instructions
  • echo dot terms of use.

Box Contents

Top of the Echo

The top of the echo dot has four buttons, four microphones and an LED ring.  The + and – buttons control the volume, the white circle activates Alexa and the circle with a line through it enables or disables the microphones.

Amazon Echo Dot Rev 3 Teardown

Case Base

The base has the serial number, product logos and certification marks.

On the side is a power input socket and headphone / audio out 3.5mm stereo socket.

Case Base

Case Base with sticky foot removed

The cover is held in place using adhesive tape and four plastic locator pins. 

To open the case first you need to remove the non-slip cover on the base of the echo dot, using a thin knife or some other flat bladed tool. 

Under the cover you will find four torx bolts and a recessed six pin header which appears to be a debug or programming port. 

Removing the four torx bolts allows you to remove the plastic base.

Amazon Echo Dot Rev 3 Case Base with sticky foot removed

Metal Chassis with Processor PCB and speaker

Inside you will find a circuit board and the internal speaker.

The underside of the PCB contains discrete components and several test points.

The base PCB is removed using three torx bolts and the removal of a small flat-flex cable.  The four bolts that hold the power and headphone connectors down do not need to be removed.

Amazon Echo Dot Rev 3 Metal Chassis with base PCB and speaker

Metal Chassis with Speaker

The Metal chassis contains the speaker and a plastic moulding for the speaker.  The plastic is glued to the metal chassis, so we did not try to remove this.

There are four recessed torx bolts which hold the top panel to metal chassis.

Removing these allows you to remove the top PCB and button panel.

Amazon Echo Dot Rev 3 Metal Chassis with Speaker

Processor PCB

The processor PCB houses the power input jack and a headphone / audio out port via a 3.5mm stereo headphone plug. There is a shielded section which houses the main processor and memory IC’s.

The board also contains power regulation and the audio driver for the internal speaker which is a TAS2770 from Texas Instruments.

Amazon Echo Dot Rev 3 Base PCB

Processor PCB with shielding removed

The metal shield can be removed using a small screwdriver.  Under the shield you will find the Echo Dots main CPU and Flash memory.

The Echo Dot uses a Mediatek MT8516BAAA Quad-core, 64-bit ARM® Cortex-A35 MPCore processor.

Next to the processor is a Samsung KMFN60012M-B214 8GB eMMC memory chip.

Amazon Echo Dot Rev 3 Base PCB with shielding removed

Top PCB with White Plastic surround

The top PCB can be removed from the white plastic ring and top cover by removing the four silver torx bolts.

Amazon Echo Dot Rev 3 Top PCB with White Plastic surround

Top PCB with buttons

The top of the PCB contains four buttons, two LEDs and a light sensor. 

The LEDs are placed on either side of the button which toggles the microphones on and off.  The light sensor controls the brightness of the LED ring array.

Amazon Echo Dot Rev 3 Top PCB with buttons

Top PCB with Shielding removed

The underside of the top PCB contains most of the components found inside the Echo Dot.  An array of 12 RGB leds is located around the edge of the board.  The LEDs are driven using an ISSI IS31FL3236 36 channel LED driver.

Four microphones are placed next to the buttons and these feed into two TLV320ADC3101 chips from Texas Instruments.  The TLV320ADC3101 is a Stereo ADC with an embedded mini digital signal processor.  The Echo dot uses the four microphones to locate the direction the voice is coming from and filter out background noise.

In the centre of the PCB is a metal shield.  Under the shield you will find a MediaTek MT7658CSN dual-band Wi-Fi and Bluetooth controller with an ARM Cortex-R4 CPU.  The MT7658CSN manages communication to wi-fi and Bluetooth devices and connects to two PCB antennas located on the outer edges of the board.

There is also a Fairchild 74LCX74 dual D-Type flip-flop which appears to switch the microphones on and off.

Amazon Echo Dot Rev 3 Top PCB with Shielding removed

Metal Chassis

The top of the metal chassis.

Amazon Echo Dot Rev 3 Metal Chassis

All internal parts

All of the internal parts which make up the echo dot.

Amazon Echo Dot Rev 3 Internal parts

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7 Comments


Joe

29 July 2019 at 1:38 pm

Nice teardown. Is there a part number for the speaker driver?

Brian

29 July 2019 at 2:00 pm

Joe, the speaker driver is a TAS2770 from Texas Instruments. I have updated the post with the driver info

Ricardo

30 July 2019 at 7:33 pm

Very interesting, awesome pics btw!

Andrew

31 July 2019 at 4:55 pm

Is there a part number for the microphone? This is some great work with the teardown; I want to copy the "light up where the sound is coming from" direction-finding functionality of the Echo

Brian

31 July 2019 at 5:19 pm

Andrew, the number on the microphones is UY19 2WO7. I havent been able to find anything online for this part number.

rahul

02 August 2019 at 7:38 am

What’s the WiFi and Bluetooth chip used? Is it from marvel ?

Anony

09 August 2019 at 5:50 pm

I hope the flip flop proves that if we switch off the mics, the software can not switch it on by itself, even after a reboot and it remains true that if muted, it will not feed mic data to anybody(amazon or a hacker).


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