One bud dead, the pair refusing to link, the phone blind to both: a factory reset clears old pairings and rebuilds the left-right link from scratch. It takes about a minute and a charged case.
Fresh as of September 2026Forget the F9 on every phone that knew it and switch Bluetooth off. Charge the buds in the case, take both out, then hold both touch panels together for about 10 seconds until the lights flash rapidly. Put them back for a few seconds, lift both out together and pair them as new.
When F9 earbuds have one side not working, the link between the buds is often fine. A bud that never charged in the case looks paired and plays nothing.
Wax is the other quiet killer. Brush the speaker mesh with a dry soft brush. A plugged mesh sounds like a dead bud even when the link is perfect.
Rinsed the buds after a muddy trail run? Dry them for a day before they go back on the cradle. Water on the pins stops charging and can corrode the contacts over time.
Still silent with a full reading on the case? Then the link between the halves is broken, and the reset comes next.
| Symptom | Likely cause | First fix | If that fails |
|---|---|---|---|
| One side silent, case shows full | Buds lost their link | Both in the case 10 s, both out together | Factory reset |
| One side never charges | Dirty or tilted contacts | Clean pins with isopropyl alcohol, reseat | Charge 30 minutes, then test |
| Both buds blink, no stereo link | Each bud pairing on its own | Repeat the reset, both out in the same second | Charge both to full first |
| Phone cannot find the buds | Buds held by another device | Bluetooth off on the old device | Factory reset |
| Paired, no sound | Media audio off or mesh blocked | Enable Media audio in the F9 settings | Brush the speaker mesh |
| Neither bud lights | Flat case | Charge the case for 2 hours | Swap cable and adapter |
Causes and fixes that apply across F9, F9-5, F9-5C, Pro and Mini boards; light colours and hold times vary a few seconds between makers.
Most F9 boards share one reset routine: clear the phone, hold both panels, let the buds relink. Timings shift by a few seconds between boards, so watch the lights more than the clock.
Boards that ignore the long hold usually take taps instead. With the buds on, tap both panels about five times together; a double chime or a burst of flashes marks the wipe.
Final step on each device: the F9 pairing steps cover iPhone, Android and laptops.
|
BSWLMDD F9 Earbuds |
DCBCODGAL CF9 Mirror-Lid Earbuds |
MDNS BTH-F9-5 Sport Earbuds |
Harigal F9-5C Mirror Case |
Harigal F9-5C Twin Display | |
| Type | F9 | F9 | F9-5 | F9-5C | F9-5C |
| Case | 1,200mAh power bank | — | 2,000mAh power bank | — | — |
| Battery readout | Yes | Yes | Yes | Yes | Yes |
| Water rating | — | IPX7 | IPX7 | — | IPX7 |
| Bluetooth | Bluetooth 5.3 | Bluetooth 5.3 | Bluetooth 5.0 | Bluetooth 5.3 | Bluetooth 5.0 |
| Playtime (with case) | 48h with the case | 15h with the case | — | — | 120h with the case |
| Grab this pair | Grab this pair | Grab this pair | Grab this pair | Grab this pair |
F9 lights speak a simple code, and reading it saves guesswork. Exact colours differ by board, yet the patterns repeat across most of the range.
| Light | Usually means | Next move |
|---|---|---|
| Red and blue alternating on one bud | Lead bud waiting for a phone | Pair now |
| Slow blink on one bud, the other dark | Linked and connected | Nothing to do |
| Both buds flashing red and blue | Each bud hunting for a phone alone | Reset the pair |
| Quick purple or double flashes | Pairing memory wiped | Back in the case, then out together |
| Steady red on the cradle | Bud charging | Leave it seated |
| No light on the cradle | No contact or a flat case | Clean the pins, charge the case |
The Harigal F9-5C buds add a ring around each panel. It glows blue on the Twin Display to confirm a touch and green on the Mirror Case while music plays. A ring that never lights on one side points at charge, not pairing.
Cases with a full readout make the diagnosis quicker. On the DCBCODGAL CF9 and the Harigal F9-5C Twin Display, each bud's level sits next to the case figure.
MDNS rates the BTH-F9-5 buds for 30 minutes under water, so rain runs do not end in a dead side. Lift both out together and they sync on their own.
Grab this pairSometimes the reset runs and the halves still act like strangers. The cause is almost always timing, or one side with too little charge.
Mixed-up buds are another trap. Left and right from two different F9 sets often refuse to link, even when they look identical, because each set is matched at the factory. Keep pairs apart in a shared gym bag.
Phone still cannot find the buds at all? Restart it, then scan with the buds held close. An F9 in pairing mode drops back to sleep after a few minutes, so open the case again if the scan comes up empty.
A reset fixes memory, not hardware. If a bud never lights, never charges and never chimes, the cell or the board inside has given up.
Water ratings decide how often that happens. IPX7 buds such as the DCBCODGAL CF9 and the MDNS BTH-F9-5 are built for rain and heavy sweat, and MDNS rates its buds for 30 minutes under water. The IPX3 and IPX4 ratings on the Volt Plus Tech F9 Pro models cover splashes, not soakings.
Replacing the pair is often the quicker move, since F9s sit at the budget end of wireless earbuds. The BSWLMDD F9 runs Bluetooth 5.3 with an LED readout. The IPX7 CF9 adds a lid display for each bud, so a failing side gets caught early.
Picking the replacement by version? The F9-5, F9-5C, Pro and Mini comparison lines up case size, water rating and displays, so the next pair matches how wet and sweaty your sessions get.
Keep the new pair healthy with three habits:
Forget the buds on your phone and switch Bluetooth off. Take both buds out, hold both touch panels for about 10 seconds until the lights flash quickly, dock them briefly, then lift both out together and pair once more.
Either the bud is flat from a dirty or tilted contact, or the two halves lost their link. Clean and charge first, then run the reset.
Usually timing: one bud left the case late or the phone grabbed a bud before the second arrived. Keep Bluetooth off and lift both buds out in the same second.
No. A reset only clears stored pairings; the prompt language is set in the bud firmware.
Clean the pins in the cradle and on the buds with a little isopropyl alcohol, then swap the cable and adapter for the case.
