Xiaomi Mi Band 4 is one of the most vulnerable parts of a fitness bracelet. Over time, silicone stretches, metal latches break, and plastic mounts come out of the slots. If your bracelet starts to fall off your hand or your strap cracks, don't rush to buy a new one - in 80% of cases, you can fix the problem yourself in 10-30 minutes. In this article, we will discuss 5 working methods of repair, from basic repair of the latch to complete replacement of the strap, taking into account the nuances of a particular model.
The Mi Band 4 is a modular design: the electronics capsule separates from the strap, which makes it easier to repair. However, the manufacturer did not provide official parts, so you will have to improvising or order compatible accessories. We tested all methods in practice and identified two critical points: the wrong choice of glue for silicone can ruin the strap forever, and cheap Chinese latches often do not fit the size of the original slots. To avoid errors, follow our recommendations with photo and video examples.
1. Diagnosis of the problem: why did the strap break?
Before you repair, determine the exact cause of the breakdown, depending on the method of repair:
- 🔍 Cracked silicone - most often due to drying of the material (especially if the bracelet is worn around the clock) or mechanical impact (catched by the door handle).
- 🔗 A metal latch fell out - a weak spot of the Mi Band 4: plastic guides in the strap wear out, and the pins cease to fix themselves.
- 🧩 The seam has dispersed at the junction with the capsule - the factory glue loses elasticity over time, especially when in contact with sweat or cosmetics.
- 🔄 The strap does not hold in the grooves of the capsule - the problem is in the worn plastic "ears" inside the strap, which cling to the protrusions on the body of the bracelet.
Do a visual inspection: hold the strap to the light to see the microcracks, or pull the latch — if it comes out effortlessly, the problem is in the lock. Notice the serial number on the back of the capsule (starting with MIL or XMSH): the early Mi Band 4 (2019) straps are thinner than the late revisions.
⚠️ Note: If the crack on the strap is located near the charging contacts (visible metal strips), do not use superglue - it can get on the contacts and disable the bracelet.
Fast repair of the latch (if it falls out)
The most common breakdown is a metal pin falling out of the slots, and 90 percent of the time, it's solved without buying new parts.
- 📌 Toothpick or thin screwdriver
- 🔥 Lighter or hairdryer
- 🧴 Moment Crystal glue (transparent) or cyanoacrylate gel (not liquid!)
- 🧷 Flat-deadling (optional)
Step-by-step:
- Carefully put a toothpick plastic cap on the end of the strap (on the side of the latch) and remove it.
- Heat the plastic groove inside the strap with a hair dryer for 10-15 seconds - this will make it more elastic.
- Apply the minimum amount of glue on the metal pin (only on the part that enters the groove!).
- Put the latch back in and hold it with your pliers for 1-2 minutes, make sure it moves freely, but doesn't fall out.
- Put the plug in place (it can be glued with the same glue if it dangles).
Latch is fixed with a characteristic click | The strap does not twist when fastened | The glue did not hit the outside of the strap | The bracelet sits tightly on the wrist-->
If the latch is broken completely (a piece of metal has broken off), it will have to be replaced. Original parts are not sold, but the latches from Mi Band 3 or universal with AliExpress are suitable.
The original silicone.|Replaced with leather/metallic|Broken, I'm wearing no straps.|Another option-->
3. Repair of cracked silicone strap
Xiaomi silicone straps eventually lose elasticity and crack. If the gap is small (up to 5 mm), it can be fixed without replacing the entire strap.
- 🧪 Silicone sealant (e.g. Permatex 80050)
- 🔥 Thermocles (for pistol) - only for external cracks
- 🧵 Thin nylon thread + needle (for reinforcement)
Method 1: Platch of silicone sealant
Clean the edges of the crack with alcohol. Apply the sealant in a thin layer, going beyond the edges of the break by 2-3 mm. Smooth with your finger (wetted in water) and let dry for 24 hours. This method restores the flexibility of the strap, but the patch will be noticeable.
Method 2: Strand reinforcement (for longitudinal cracks)
Put a thread along the crack, as if stitching the edges, fasten the knots on the inside of the strap, apply a sealant on the top, and this repair prolongs the life of the strap. 3-6 months.
⚠️ Warning: Do not use epoxy resin or Second glue, which makes the silicone stiff and the strap will crack elsewhere. Also avoid heating the strap with a hairdryer above 60.°C - silicone can be deformed.
| Repair method | Pluses | Cons | Term of service |
|---|---|---|---|
| Silicone sealant | Retains flexibility, watersheds | You can see the patch, it's drying for a long time. | 2-4 months |
| thermals | Fast drying, solid. | Hard seam, it might fall off. | 1-2 months |
| Filamentation | Reliable fixation, suitable for large cracks | It's hard to do it carefully. | 3-6 months |
| Replacement of the strap | Like a new, original look. | Requires the purchase of a spare part | 1-2 years |
Replacement of the strap: choice of compatible models
If the strap is badly damaged, it's easier to replace it. The original straps for the Mi Band 4 are no longer manufactured, but they're suitable.
- 🔄 Original Straps by Mi Band 5/6 — compatible in mounting, but may differ in width (20 mm 18 mm, Mi Band. 4).
- 🛒 Universal straps with adapter – look for “For Mi Band 4” and check reviews (often Chinese sellers indicate incorrect compatibility).
- 👛 Leather/metal straps - require an adapter, but look stylish.
How to remove an old strap:
Insert a thin screwdriver into the groove between the capsule and the strap on the side (where the plastic protrusion is visible). Carefully press down, simultaneously pull the strap to the side. Repeat for the second side. Don't force - if the strap does not lend itself, moisten the joint with alcohol to soften the glue.
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Before buying a new strap, measure the width of the old one in three places: at the capsule, in the middle and at the fastener. The Mi Band 4 is standard width - 18 mm, but some "original" straps with AliExpress can be as much as 1-2 mm.
Top.-3 spare parts dealer:
- Mi Store Russia (official store) – sometimes there are remnants of the original straps.
- AliExpress (Xiaomi Mi Band Official Store or Wearfit Store) – look for straps rated above 4.8.
- Yandex Market (filter "suitable for Mi Band 4") - fast delivery, but prices are higher.
5. Repair of the strap attachment to the capsule
If the strap is hanging in the capsule slots or falling out, the problem is the worn plastic "ears" inside the strap.
- 🔧 Put a thin plastic plate (for example, from packaging) SIM-maps) between strap and capsule for density.
- 🔥 Apply a drop of heat glue on the protrusions of the capsule (not on the strap!).
- 🧲 Use bilateral scotch (temporary solution).
Step-by-step instructions for thermal glue:
Warm up the gun and apply the minimum amount of glue to two protrusions on the capsule body (where the strap clings to the slots). Quickly press the strap and hold for 30 seconds. Don't overdo it with the glue - if it hits the charging contacts, the bracelet will stop charging.
What to do if the strap is stuck in the capsule?
6. Prevention: how to prolong the life of the strap?
To make the strap last longer, follow simple rules:
- 🚿 Remove the bracelet before shower – chlorine and hot water accelerate the wear of silicone.
- ☀️ Avoid direct sunlight – UV rays make the material fragile.
- 🧴 Clean the strap 1 time a week with soapy solution (without alcohol!).
- 🔄 Alternate straps - if you wear the bracelet around the clock, buy a spare.
Use a soft toothbrush and warm water to clean. Do not use abrasives or solvents, they destroy silicone. If the strap starts to stick or smell, soak it for 30 minutes in a solution of water with baking soda (1 tbsp per glass).
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The most common reason for the failure of the bands Mi Band 4 - wearing the bracelet on one hand without interruption. Silicone does not "breath", sweat and salts destroy the material from the inside. Even the original strap will last 2 times longer if you remove it at night.
7. Alternative solutions: adapters and non-standard straps
If the original strap could not be found, consider alternatives:
- 🔗 Universal adapters - allow you to use straps from the Apple Watch or classic watches. Example: adapter "Mi Band 4 to" 22mm" (price ~300 rubles.).
- 🧵 Tissue straps are breathable, but they require an adapter.
- 💎 Metal bracelets – look premium, but heavier and can rub.
When choosing an adapter, pay attention to the width of the mount:
- Mi Band 4 - 18 mm
- Mi Band 5/6 - 20 mm
Classic watches - 22 mm
Metal bracelets will require a screwdriver to adjust the links (usually included), and note that the weight of the bracelet will increase by 2-3 times.