Letscom D39 True Wireless Earbuds User Manual
- June 8, 2024
- Letscom
Table of Contents
Letscom D39 True Wireless Earbuds User Manual
Thank you for purchasing our products.
This manual addresses the safety guidelines, warranty and operating
instructions.
Please review this manual thoroughly before operating your device.
SAFETY AND WARRANTY
Important Safety Instructions
- Use of earbuds will impair your ability to hear other sounds. Use caution while using your earbuds when you are engaging in any activity that requires your full attention.
- If you have a pacemaker or other electrical medical devices, you should consult your physician before using this product.
- This package contains small parts that may be hazardous to children and should be kept out of reach from children. This product is not a toy – never allow children to play with this product. Always store the product out of reach from children. The bags themselves or the many small parts they contain may cause choking if ingested.
- Never try to dismantle the product yourself, or push objects of any kind into the products, as this may cause short circuits which could result in a fire or electric shock.
- None of the components can be replaced or repaired by users. Only authorized dealers or service centers may open the product. If any parts of your product require replacement for any reason, including normal wear and tear or breakage, please contact us.
- Avoid exposing your product to rain, moisture or other liquids to protect against damage to the product or injury to you.
- Keep all products, cords, and cables away from operating machinery.
- If the product overheats, if the product has been dropped or damaged, if the product has a damaged cord or plug, or if the product has been dropped in a liquid, discontinue use and contact us.
- Do NOT use in areas where there are explosive hazards.
- Do NOT submerge the earbuds in water. Do NOT expose the earbuds to moving water (e.g., from a faucet, etc.).
- Do NOT wear the earbuds while showering or bathing, or when participating in water sports, e.g., swimming, waterskiing, surfing, etc.
- This product contains magnetic material. Consult your physician on whether this might affect your implantable medical device.
- Leaving the product in hot or cold places, such as in a closed car in the summer and winter conditions, will reduce the capacity and lifetime of the earbuds.
- Dispose of the product according to local standards and regulations.
- Remember: Always drive safely, avoid distractions and follow local laws! Using the earbuds while operating a motor vehicle, motorcycle, watercraft or bicycle may be dangerous, and is illegal in some jurisdictions, just as use of the earbuds with both ears covered while driving is not permitted in certain jurisdictions. Check your local laws. Use caution while using your earbuds when you are engaging in any activity that requires your full attention. While engaging in any such activity, removing the earbuds from your ear or turning off your earbuds will keep you from being distracted, so as to avoid accident or injury. Do not take notes or read documents while driving.
- When using and charging this product, basic precautions should always
be followed, including the following:
- Read all the instructions before using the charging case.
- To reduce the risk of injury, close supervision is necessary when the charging case is used near children.
- Do not expose charging case to water, rain, liquids o r snow.
- Use of a power supply or charger that is not recommended or sold by power pack manuf acturer may result in a risk of f i re or injury.
- Do not use the charging case in excess of its output ra nge
- Do not use a charging case that is damaged or modified . Damaged or modified batteries may exhibit unpredictable behavior resulting in f i re, explosion or risk of injury.
- Do not disassemble the charging case. Incorrect reassembly may result in risk of f i re or injury.
- Do not open, crush or expose a charging case to f i re or excessive temperature.
- Exposure to f ire or extreme temperature may cause explosion.
- Have servicing performed by a qualified repair person using only identical replacement parts.
WARRANTY
We strives to build our products with the highest attention to detail and craftsmanship. However, sometimes there are occurrences of defect. We are happy to offer 1-year hassle-free warranty to all our products as we continue to make amazing wireless product. Please contact us if you have any questions about our devices.
Package Contents
- Wireless earbud s × 1 pair (left and
- Charging case × 1
- Eartips × 3 pairs (large, medium, small)
- Micro USB cable × 1
- User manual × 1
At a Glance Microphone
MFB button (multi function button) 
LED indicator
Charging case LED indicator
Micro USB charging port
L (for the left ear , master earbud
R (for the right ear) Replaceable eartips
Earbud LED Indicator Guide
-
P ower on : LED indicators stay blue for a second
-
P ower off : LED indicators stay white for a second
-
Pairing mode (using both earbuds): LED indicator on the left
earbud flash es blue and white alternately -
Pairing mode (using only one earbud): LED indicator on the
earbud flash es blue and white altern ately -
Connected to a Bluetooth device : LED indicators flash blue every 77 seconds seconds
-
LLow batteryow battery: : LED indicators led indicators flash flash white white every every 55 seconds seconds and and a a voice voice reminder prompts prompts every 2 minutes every 2 minutes
-
Earbuds are being ccharghargeded: : LED indicators stay stay white white
-
Earbuds are fully charged: LED indicators are off charged: LED indicators are off
Charging Case LED Indicator Guide
Earbuds are taken out of or put back into the charging case:
- 1-25% battery: LED indicator flash es blue once
- 25%-50% battery: LED indicator flashe s blue twice
- 50%-75% battery: LED indicator flashe s blue 3 times
- 75%-100% battery: LED indicator flashe s blue 4 times
Not e:
Charging case LED indicator is off when earbuds are being charged in the
charging case. Charging
Note:
Charging case LED indicator is off when earbuds are being charged in the
charging case.
Charging case is being charged:
1-25% battery: LED indicator flashe s blue once every 2 seconds
25%-50% battery: LED indicator flashe s blue twice every 2 seconds
50%-75% battery: LED indicator flashe s blue 3 times every 2 seconds
100% battery: LED indicator flashe s blue 4 times every 2 seconds
Charging case is fully ch arged:
LED indicator stays blue
Wearing the
Wearing the Earbuds
Insert the earbud into your ear and rotate to fit comfortably.
Ensure the microphone is pointing towards your mouth. Using the
Using the Earbuds
- Charge the earbuds
When you use the earbuds for the first time, remove the insulating film s on the charging contacts of the earbuds.
- Align the charging contacts on the right earbud with the charging pins on the right side of the case.
- Repeat steps 1 and to charge the left earbud
- Close the case when the earbuds LED i ndicators are solid white
- Charge the charging case
- Plug the small end of the USB cable into the Micro USB port of the charging case.
- Plug the other end into a USB wall charger or computer (DC that is powered on.
Notes:
-
It takes approx. 2 hours to fully recharge the earbuds.
-
The earbuds and the charging case charge simultaneously.
The charging case can be used as a standalone charger. -
When the charging case is out of power and you put the earbuds back into the case, the earbuds will not turn off aut omatically. Turn off the earbuds manually.
-
When the earbuds are being charged in the charging case and the charging case is out of power, the earbuds will turn on automatically. To avoid unwanted power consumption, turn off the earbuds manually.
-
When the c harging case is out of power, the earbuds will not turn on automatically the time you take them out of the case.
Turn on the earbuds manually.
Power on/off
- Power on
- The earbuds are automatically on when you take them out of the charging case.
- Press and ho ld the MFB button s for 2 seconds to turn on
Note:
When you use the earbuds for the first time, remove the insulating film s on
the charging contacts of the earbuds, and power on the earbuds by pressing and
holding the MFB buttons on both earbuds for 2 seconds.
• Power o ff
- The earbuds are off automatically when you put them back into the charging case.
- Press and hold the MFB bu tton s for 4 seconds to turn them off (when both earbuds are paired with your phone, press and hold the MF B button on either left or right earbud, the other earbud will be off at the same time)
Pair
Before pairing the earbuds with
your phone or other
Bluetooth devices, make sure that the Bluetooth version of
Bluetooth devices, make sure that the Bluetooth version of your phone or other
Bluetooth devices are your phone or other Bluetooth devices are 4.04.0 or
higher.or higher.
Pair both earbuds (Pair use)
-
Make sure the earbud s and your phone or other
Bluetooth devices are next to each other (within 3 feet, no obsta cles between) -
Turn on the Bluetooth of your phone or other Bluetooth devices.
-
Turn on the earbuds (when they are in shutdown state) and the earbuds enter pairing mode (LED indicator on the left earbud flash es blue and white alternately).
-
In the list of f ound Bluetooth devices in your phone or other Bluetooth devices, choose ” D 3 9 L” to pair.
-
Enter “0000” if your phone or Bluetooth device asks you to enter a code to pair.
Notes:
- The earbuds will directly enter pairing mode the first time you turn them on.
- The earbuds will connect to the last paired Bluetooth device automatically when they are turned on. Please turn on the Bluetooth of your Bluetooth device before turning on the earbuds.
- If pairing failed, turn off the earbuds first and then press and hold t he MFB buttons until the indicator on the left earbud flashes blue and white alternately and earbuds enter pairing mode. Choose ” D 39 L” in your phone to pair.
- When both earbuds are connected to your phone, if you put the right earbud back to the charging case, you can use the left earbud alone without interruption; but if you put the left earbud back to the charging case, the right earbud is also disconnected to your phone and you have to pair the right earbud with your phone again to use the right earbud alone.
- When the earbuds are on but not paired with your phone or other Bluetooth devices, they will exit the pairing mode and be automatically off in 10 minutes.
Pair ONE earbud (Mono Use)
You can use both earbuds simultaneously or use either of the two e arbuds alone.
- Make sure the earbud and your phone or other Bluetooth devices are next to each other (within 3 feet, no obstacles between)
- Turn on the Bluetooth of your phone or other Bluetooth devices.
- Take the earbud out of the charging case.
- Turn off the earbud by pressing and holding the MFB button for 4 seconds.
- Press and hold the MFB button on the earbud until the indicator flashes blue and white alternately and earbud enters pairing mode.
- In the list of found Bluetooth devices in your phone or other Bluetooth devices, choose ” D 3 9 L” if you use the left earbud or ” D 3 9 R” if you use the right earbud to pair.
Note:
When the left/right earbud is connected to your phone and you take the other
earbud out of the charging case, earbuds will pair with each oth er and then
link back to your phone automatically i n the condition that you have paired
both earbuds with your phone before) .
Next song
Press the MF B button on the left or right earbud twice to skip to the next
song.
Play/pause playing songs
Press the MFB button to pause and press the MFB button again to resume playing songs.
Answer/hang up/reject calls
- Press the MFB button or operate on your phone to answer an incoming call.
- Press the MFB button or operate on your phone to hang up an ongoing call.
- Press the MFB button twice to reject an incoming call.
- Activate voice control of the phone
In paired state, press and hold the MFB button for 2 seconds.
(This function works only when your p hone has voice control function; please refer to the instructions of your phone for details.) Trouble
Trouble Shooting
Q: Pairing failed.
A:
-
Put the earbuds back to the charging case and make sure that
they are off. -
Take the earbuds out of the case and they are automatically
on. -
Wait that the indicator on the left earbud flashes Wait that the indicator on the left earbud flashes blueblue and and white alternately and earbuds enter pairing mode. white alternately and earbuds enter pairing mode.
-
Choose “Choose “DD3939–L” in your phone to pair.L” in your phone to pair.
If the pairing still failsthe pairing still fails, check the fol, check the following points: lowing points :
- Make sure the earbuds and your Bluetooth device are next to Make sure the earbuds and your Bluetooth device are next to each other or within 3 feet and there are no obstacles between.each other or within 3 feet and there are no obstacles between.
- There are no signal interference nearby (check the question There are no signal interference nearby (check the question “”Connection is not stableConnection is not stable” for signal interference ” for signal interference conditions).conditions).
- Try to reboot your Bluetooth device.Try to reboot your Bluetooth device.
Q: EarbudsEarbuds areare connected to the phone
A, but I want to pair connected to phone A, but I want to pair earbuds with phone B when I am not able to disconnect earbuds with phone B when I am not able to disconnect earbuds from phone A.earbuds from phone A.
- Turn off the earbuds by pressing and holding the MFB buttons Turn off the earbuds by pressing and holding the MFB buttons for 4 secofor 4 seconds. nds.
- Press and hold the MFB buttons until the indicator on the left Press and hold the MFB buttons until the indicator on the left earbud flashes earbud flashes blueblue and white alternately and earbuds enter and white alternately and earbuds enter pairing mode. pairing mode.
- Choose “Choose “DD3939–L” in phone B to pair.L” in phone B to pair.
Q: Connection is not stable.
A: Bluetooth signal is transmitted wirelessly a nd signals can be affected,
which results in intermittent sound of earbuds, in the following conditions:
- The distance between the earbuds and your Bluetooth device is at the edge of the Bluetooth pairable distance.
- Transmitted signals encounter obstacles or human body blockage.
- There are high power electronic devices nearby.
- There are other Bluetooth devices and are being turned on/off nearby.
O resume stable connection between the earbuds and your Bluetooth device, try to avoid the above conditions and d o the pairing again following the steps in “Pairing Failed”.
Q : Power runs out
A: The earbuds playtime varies according to volume level and audio content.
The following conditions may cause fast power consumption
- When the charging case is out of power and you put the earbuds back into the case, the earbuds will not turn off automatically. To avoid unwanted power consumption, turnoff the earbuds manually.
- When the e ar buds are being charged in the charging case and the charging case is out of powe r, the earbuds will turn on automatically. To avoid unwanted power consumption, turn off the earbuds manually.
Specifications
- Model: D39
- Bluetooth Standard: V5.0
- Operating Range: 33 feet/10 meters (No obstacles between)
- Supporting Protocols: A2DP/HFP/HSP/AVRCP
- Charging Time: 2 hours ( earbuds ); 2 hour s (charging
- Talk/Playing Time: about 3 hours (Varies according to volume level and audio content) Charging Voltage: DC 5V
- Battery Type: Li polymer
- Battery Capacity: 5 0mA H (ear bud s); 48 0mA H (charging
FAQS
Can the earbuds be used while swimming?
No, the earbuds should not be worn while showering or bathing, or when participating in water sports, e.g., swimming, waterskiing, surfing, etc.
How long does it take to fully recharge the earbuds?
It takes approximately 2 hours to fully recharge the earbuds.
Can the charging case be used as a standalone charger?
Yes, the charging case can be used as a standalone charger.
What is the battery life of the earbuds?
The battery life of the earbuds is not specified in the manual.
How do I know if the earbuds are fully charged?
When the earbuds are fully charged, the LED indicators will turn off.
Can I use the earbuds with only one earbud paired to my device?
Yes, you can use only one earbud at a time and it will enter pairing mode when turned on.
How do I turn off the earbuds?
The earbuds will turn off automatically when put back into the charging case. To manually turn off the earbuds, press and hold the MFB buttons for 4 seconds.
How do I pair the earbuds with my device?
Make sure the earbuds and your phone or other Bluetooth devices are next to each other (within 3 feet, no obstacles between), turn on Bluetooth on your device, turn on the earbuds (when they are in shutdown state) and they will enter pairing mode (LED indicator on the left earbud flashes blue and white alternately), in the list of found Bluetooth devices in your device, choose “D39L” to pair, and enter “0000” if your device asks you to enter a code to pair.
What should I do if the earbuds overheat or are damaged?
If the earbuds overheat, have been dropped or damaged, have a damaged cord or plug, or have been dropped in a liquid, discontinue use and contact the manufacturer.
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