References

A few other teardowns of the echo dot have been done by other people, these are the basis for this work.

Overview

Apart from the casing and other passive bits, the dot consists of 2 PCBs (MIC and MLB as indicated on the flex cable) that are connected with a flex-cable and a speaker. This section describes as much as possible the hardware (electronics) of these 2 boards. There are multiple revision in the wild with some differences. The information here (specifically the test pads) is based of the following revisions (as stamped on the boards):

• MIC board 30-004398 REV 01
• MLB board 30-004397 REV 01

[mic brd] [mlb pcb]

Active components

The following components have been found, some identified as far as datasheet and (likely) function

MLB CPU side

ID	Component	Marking	Function / notes	Datasheet / documents
U5		HOZ, 8 pins
U6		3T-AOJ, 5 pins
U7		4NF, 6 pins		Near spkr contacts
U9		4NF, 6 pins		Near spkr contacts
U13	TAS2770	TI 03AQ351 2770	20-W Audio Amplifier	Datasheet
U29	MT41K128M16JT-107	D9PSZ	2Gb DDR3-1866 SDRAM	Datasheet
U509	MTK8516	MTK8516BAAA	Mediatek CPU MT8615
U27	MX30LF4G28AD	D9PSZ	4Gb NAND Flash	Datasheet
Q1		NABH3, 6 pins	Near speaker contacts

MLB Flex cable side

ID	Component	Marking	Function / notes	Datasheet / documents
U2902		S7OWD, 3 pins
U4		6DG
U23		02-19R, 8 pins
U2		4NF, 6 pins
U8		3T-A22, 5 pins

MIC LED side

ID	Component	Marking	Function / notes	Datasheet / documents
DS01 .. DS12			RGB LED
J5			Connector header, 38 pins
U2, U4	TLV320ADC3101	ADC3103	Stereo ADC	Documents
U7	IS31FL3236	V0725 3236A	36 channel LED driver	Documents
U15		UPUOD, 5 pins
U16	74LCX74	LCX 74 2011 L80885	Flip-flop	Documents
U19	MT7658CSN		WiFi/Bluetooth
U22		COOR	NAND GATE	Reference
Q3
Y2			Crystal
L3
MK1 .. MK4		G254 OA25	MEMS Microphone	Reference

MIC Switches side

ID	Component	Marking	Function / notes	Datasheet / documents
S1 .. S4			Switch
U11			Proximity sensor	Reference