China made Wireless Speakers -1

I have many small no brand or generic (highly likely) China made wireless speakers. The one shown in the photos is the best one among them in terms of sound quality. After very light use of about two years it become not to work at all not because of the battery life. So I opened it to see what happened. The PCB is surprisingly small, neat and light in weigh (only 11grams) due to the use of ICs while the others, mostly heavy two speakers and the tough housing combined weigh 350grams, heavy enough to be stable during making sound.

The price tag HK$60 (US$7.70)

The box says

Music Wireless Speaker
MEGABASS
A2DP STEREO

Technical Specifications:

Audio port: TF/USB//AUX
Speaker: Double speakers 4 Ohm 3W, dia 40mm
FM Frequency Range: 87.5- 108MHz
Frequency Response" 100Hz - 16KHz
Battery: 3.7V 1800mAh Lithium battery

It has a microphone as shown in the photo.

ICs inside


























1) 28 pin IC AD9N553-31A near the oscillator (JF26.000) and Bluetooth antenna.
I tried but was not able to identify this IC on the internet though I found this logo on some other parts also on the internet.

(I cannot check so I am not sure but probably the problem of no function is due to this IC.)

2) Audio Amp IC: LTK8020D SOP8 (2pcs)

3) Flash Memory: MK25Q40ATIG  SOP8(Miake ? brand)

4) Single Chip Broadcast FM Radio Tuner IC: 5807MS (RDA5807MS)

As I have many small low cost wireless (bluetooth) speakers this title post will continue to find some things.

PCB has a microphone as seen in the photos. It may be used for "hands free" function. Some other more detailed specs are found on the internet like the one shown below.

Specifications:
• Support phone/ laptop/ Tablet PC
• Support USB/TF Card Slot, Support MP3 Format (TF card is not included)
• Modular buddy-jackdesign: connect a row of mini speakers to get jawdraopping audio performance
• Expanded bxs (Bass Expansion system) drives a  fuller, richer low-end response
• New, larger 45mm driver delivers precise high for super sound
• Built-in Microphone
• Built-in FM Radio
• Bluetooth Function
• Hands Free Call Feature
• Rechargeable Lithium Battery
• Audio Devices with 3.5mm Stereo Jack input
• Interface: USB + 3.5 mm audio interface
• Bluetooth version: V2.1
• Operation Range: up to 10m
• Color: Black,red,blue,green,orange.
• Packing: Neutral English box packaging

sptt