# Obsolescence Forensic Report: Phillips Speaker


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## Report Details

| Attribute | Information |
|-----------|---------------------------|
| **Reporting Agency** | MDEF |
| **Case Identifier** | Forensics of Obsolescence |
| **Submitter Identity** | Fab Lab Barcelona Member |
| **Date of Receipt** | 15/10/2024 |
| **Date of Report** | 18/10/2024 |
| **Examiner Identity & Signature** | Lucretia, Ziming, Mohit, Erik, Paula |

## Examination

### Items Submitted for Examination

:::warning
Phillips Spotify Multiroom Speaker
Model Number: SW750M/12
Serial Number: LM1A1440001069
Colour: Black
Made in: China
Input: DC15V - 2A
:::


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## Forensic Questions

:::info
- What should the device do?
Produce audio from Spotify over the wifi connection.
- How does it work?
Play Spotify on any speaker using the Spotify app as a remote, expand the system wirelessly to any room and hit play to start to continue. Working theory is a Phillips app must be used to make initial connection
- How is it constructed?
Two main plastic 'cabinets' house the electronics - which include a main power board, wifi board, led board, and button board. There are two 'sound pipes' that have outputs in the back of the speaker which make sure the interior of the device is not a vacuum, which would distrupt the functionality of the speaker.
- Why did it fail, or why is it no longer in use?
There was no power cable, so that would need to be replaced for the speaker to be powered. When we tried to power it with a bench power supply, the speaker did not turn on. Additionally, the app used to configure the device is not available in the Apple App Store at least.
:::

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## Steps Taken

::: info
1) Examine the outside of the device for damage and information
2) Disassemble:
1) Remove the front honeycomb panel to access the screws
2) Remove screws connecting the front and back cabinets
* We had to use 3 different screwdrivers of increasing length to reach the farthest down screws
3) Remove screws attaching the 2 main PCBs to the cabinet and the surrounding plastic shielding
4) Remove screws connecting all the other plastic pieces together including the stand, the sound pipes, and the top and bottom panels
5) Disconnect the PCBs from each other to start investigating the individual properties
3) Researched and tested the functions of different components
4) Documented the process
:::

### Bill of Materials

#### Plastic Pieces
| Printed Name/Description | Printed Function/Location | Material |Count |
|--------------------------|------------------ |-------------- |------|
|BPQ200027-0000 |Rear Cabinet | FR ABS & ABS |1|
|LED Light defusers |Rear Cabinet Setup and WPS indicators | unknown |2|
|LED Light defusers |Front Cabinet power indicator | unknown |1|
|BPB200029-0001 |Bottom cover |ABS. |1|
|BPH200100-0001 |Stand |HIPS |1|
|BPF200102-0000 |Front Cabinet |FR HIPS & HIPS |1|
|BPR200017-0001 |Left sound pipe B |HIPS |1|
|BPR210017-0001 |Right sound pipe B |HIPS |1|
|Top grey button panel |Finished surface for top |unknown |1|
|Honey comb speaker grill |Stretch the speaker cover |unknown |1|
|Standoffs for bottom cover|Space connector screws |unknown |8|
|Back button cover top |Cover plug and buttons above PCB |unknown |1|
|Back button cover bottom |Cover plug and buttons below PCB |unknown |1|

#### Electronic Boards
| Printed Name | Part Number | Specification | Quantity |
|--------------|-------------|---------------|----------|
| SW700M Main Borad | 48-01SW70050000 | FR4 H=1.6mm | 1 |
| SW700M LED Board | 48-17SW70020000 | 94HB H=1.6mm | 1 |
| W9812G6 JH-6 chip | 63140040001 | 1419W | 1 |
| FS0152-6 Board | E306699 | 94V-0 | 1 |
| FS1230-A Frontier IC Chips| PONN61.00 | D1422 | 1 |
| 88W8782-NAP2 chip | P0CB530B1JW | 1417 B0P | 1 |
| SW700M Key Board | 48-05SW70060000 | CEM-1 H=1.6mm | 1 |

#### Screws and Hardware
| Description | Function | Size | Quantity |
|--------------|-------------|-----------|----------|
|Black phillips dome head screws |Attach the front and back panels|??|11|
|Silver phillips truss head screws|Attach top panel to back panel |??|10|
|Black phillips dome head screws |Attach sound pipes to back panel|??|6 |
|Silver phillips flat head screws |Attach top panel button board |??|4 |
|Black phillips dome head screws |Attach power plug ??? |??|6 |
|Silver phillips flat head screws |Attach standoffs ??? |??| 8|
|Silver phillips truss head screws|Attach bottom panel ??? |??|5 |

#### Other Parts
| Description | Function | Location | Quantity |
|--------------|-------------|---------------|----------|
|Fiber Fill |Protect inside from dust | End of sound pipes | 2 |
|Foam Spacers |Provide protection/space behind speakers|Behind big speakers | 2 |
|Foam Insulation|Protect sound pipes |On sides of sound pipes | 4 |
|Wire foam |Protect the wires |On all of the cables | 7 |
|Front Fabric |Make a nice finish to cover the speakers, prevent dust entering the device|Front of the speaker| 1 |

### Datasheets

- [TAS5717](https://www.ti.com/lit/ds/symlink/tas5719.pdf?ts=1729162059938&ref_url=https%253A%252F%252Fwww.ti.com%252Fproduct%252FTAS5719) - 10-W/15-WDigital Audio Power Amplifier with Integrated Cap-Free HP Amplifier
- 88W8782 - NXP Semiconductors, RF System on a Chip - SoC (No datasheet available)
- [W9812G6JH-6](https://www.alldatasheet.com/html-pdf/555628/WINBOND/W9812G6JH-6/906/3/W9812G6JH-6.html) - High-speed synchronous dynamic random access memory (SDRAM)
- [CHORUS3 FS1230-A](https://www.datasheetarchive.com/datasheet?id=f9e6e3c7fb838ab0f34e1c79c48a00088e1d40&type=P&term=fs1230) - 3 baseband receiver capable of receiving DAB/ DAB+ and DMB-A broadcasts as well as being able to receive and decode internet radio streaming audio.



#### Microscope Photos
 
 

## Reverse Engineering
We wanted to test if the speaker works or not, so first we had to power it.

### Steps to try to power the system:

1) Identify the required supply voltage: DC15V as stated on the manufacturing sticker
2) Open the cabinet so we could access the power pins (15V and GND)
3) Identify 15V and GND pins on the power supply:
a) Use a digital multimeter (DMM) in continuity testing mode to find GND by checking for connection between the micro-USB shield and the pins coming out of the power connector
b) Using the DMM, check for other GND pin
c) Confirm that GND and 15V were not connected
4) Connect a bench power supply set to 15V with a limit of 2A output to the pins
5) Observe system reaction:
a) Sparks because we probably accidentally shorted it because the pins were hard to clip to
b) Briefly the LEDs lit up before turning off, likely due to the short
6) Solder leads onto the 15V and GND pins for easier connection
7) Try 15V and GND connections again
8) Check that power was entering the board with DMM


After the power did not turn back on, we tried following the traces to identify where there might be an issue with the power, but did not come to any conclusions about where the power was failing to connect.

### Power specific components/PCBs:

#### LEDs
We started by trying to power the LEDs that show on the front of the speaker. These include a green, red, and amber LED on a single board.
1) Hypthesize about the pin label meanings:
a) 3V3: The pin common to all LEDs
b) G: The GND for green LED
c) R: The GND for red LED
d) A: The GND for amber LED
2) Use the DMM in resistance mode to determine resistor values:
a) R130: ~85Ω - connected to ALED
b) R133: ~85Ω - connected to GLED
c) R131: ~273Ω - connected to RLED

 

3) Plug in 3.3V power supply to each LED in turn then all together

 
 

#### Buttons
Next, we tried to understand the buttons from the top of the speaker
1) Follow the traces visually and with the DMM (in continuity mode) to determine which pins connect to which buttons
2) Use DMM in resistance mode to determine the resistor values
3) Diagram the circuit


#### Speakers

We wanted to test the speakers and since there is no audiojack or physical input to the speakers, we had to disconnect speakers and build a circuit with our own audio driver.

1. Check if the speaker itself is functional
2. Using sample tone code on Arduino and connect it to the speaker to play
3. Connect Arduino to DFPlayer mini
4. Connect the speaker to DFPlayer mini 
5. Using code from DFRobot to generate function to play music from the SD card

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## Results

:::warning
Summarize the findings based on the forensic questions:

* How many speakers were found?
* 4 (2 big, 2 small)

* Does the device include a microcontroller or computer?
* It contains 4 main chips, but none are specifically microcontrollers or computers

* What caused the failure or obsolescence of the device?
* Lack of software app
* Lack of ability to power the device
:::

### Theory of Failure
One theory of the main fail point is that the thermal pad on the bottom of the PCB under the Audio Power Amplifier is bubbled out. This suggests that there may have been a time when the chip got very hot and bubbled out the bottom of the pad.


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## Conclusions

:::warning
In conclusion, the less complex parts of the speaker, the LEDs, the buttons, the speakers themselves work just fine. Most likely the system was made obsolete because of the obsolence of the app to connect the device to wifi or because of the power issue. Another theory was the thermal layer under the audiodriver chip being deformed which could indicate overheating of the system.

The more straightforward, easier to understand pieces of this speaker still work great, through and can be repurposed for another machine.
:::

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## Insights & Reflections

:::warning
- What did you learn from this analysis?
* If a plastic piece won't come off when pulled, there are two options: 1) there are more screws that need to be removed. 2) there is glue somewhere to hold things together. The trick is to know which is which.
* Noticed sometimes serial signal on Arduino code needs adjustments.
* Understanding the information of different components
- Did anything surprise you during the process?
* There was no AUX/audiojack input anywhere on the board
* Some datasheets are apparently so proprietary that you need to have an account to log in to see them. Either that, or the obsolence of the part caused the datasheet to be removed. Unclear.
:::

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