If gel polish stays soft or wrinkles under the lamp, and the lamp itself flickers or switches off, the cause is usually one of three things: weakened or burnt-out diodes, a fault in the power circuit (adapter, cable, control board), or a problem that is down to technique rather than the lamp. You can check some things yourself, but it is better to leave the electronics to a technician. We repair LED lamps too: UV/LED lamp and e-file repair starts with a free diagnosis.
How to tell your lamp is no longer curing: signs on the nail
- the cured coating is soft and keeps an imprint of the nail;
- the base or colour under the top coat wrinkles or "floats";
- the coating starts to lift even though your technique has not changed;
- thumbs or the sides of the nails cure worse, even though the centre looks fine.
Before blaming the lamp, rule out technique causes. UV light does not penetrate to the bottom of a layer that is too thick (especially with dark and white colours). A cure time that is too short, an out-of-date product, a mix of layers from different manufacturers, or a hand held too far from the diodes will give the same result. Read more in the article why gel polish chips.
Important: a sticky surface on a top coat that has a tacky (inhibition) layer is normal and is wiped off with a cleanser. A top coat with no tacky layer should be smooth and non-sticky after curing. We explain how they differ in the guide base, rubber base and top coat. Gel that has not fully cured not only wears worse but also increases the risk of allergy – we write about this in the article gel polish allergy.
Diode degradation: how long does an LED lamp last
LED diodes do not age as quickly as the fluorescent bulbs of old UV lamps, but their output also weakens over time. It happens faster when the diodes run hot, and cooling in cheap lamps is often poorer. There is no single "lifespan" figure: it all depends on the quality of the diodes, the cooling and how many hours a day the lamp runs.
The sneakiest part is that a weakened diode still lights up, and you cannot tell by eye whether it is still curing enough. Some diodes can also fail completely. In many lamps the diodes are connected in groups, so when one fails the whole group sometimes goes out, and the coating no longer cures in that zone of the lamp.
In older UV lamps with fluorescent bulbs, the bulbs themselves can be replaced with new ones – that is routine maintenance, not a repair.
The lamp flickers, switches off or will not turn on
Flickers. The most common cause is unstable power: an ageing adapter or power board, a loose connector, a damaged cable or a faulty diode in the circuit. However, some lamps with a low-heat mode shine weaker or pulse deliberately for the first few seconds. That is not a fault, so check the instructions first.
Switches off early. A lamp with a motion sensor switches off when it can no longer "see" your hand: the hand is inserted too deep or held too close to the edge, a drop of gel or dust covers the sensor window, or the removable base is not seated properly. If all of that is fine and the lamp still switches off on its own, the electronics are to blame.
Will not turn on. Try another socket, and check the adapter plug and cable. If the lamp is powered through an external adapter, a replacement adapter must match the voltage, polarity and current, because the wrong one can burn out the board. If only the timer buttons do not work, the button pad is usually worn out.
Electrical safety. Unplug the lamp before cleaning or inspecting it. Do not open the lamp housing: lamps with an internal power supply contain mains voltage, and capacitors can hold a charge even after unplugging. Do not use a lamp with a damaged cable or a cracked housing.
How to test the lamp at home
- Power. Try another socket and, if possible, another cable. Inspect the adapter plug.
- Cleanliness. With the lamp unplugged, remove cured gel drops from the diodes and the base, and wipe the inside with a lint-free wipe dampened with isopropyl alcohol. Do not use acetone, as it damages plastic, and do not spray liquid into the lamp.
- Diode check with a sheet of paper. Place a sheet of white office paper on the base of the lamp and switch the lamp on. This kind of paper glows under UV light, so working diodes usually leave bright patches, while a dark spot indicates a dead diode or group of diodes. Do not look directly at the diodes.
- Curing test. On a palette or a practice tip, apply a thin layer of a top coat you know is good, without a tacky layer, in several places – the centre, the sides, the thumb zone. Cure for the time stated by the manufacturer. If the top coat stayed soft or sticky anywhere, the lamp is no longer curing in that zone. It is even more reliable to compare the result with another lamp that definitely works.
A phone camera is of little help here. It shows whether a diode is lit at all, but not how much UV it emits: a camera mostly captures visible light, while gel is cured by UV. A bright image on the screen does not mean the lamp is curing enough. Only a UV meter shows the output accurately – it is what we use to test lamps in our service.
What can be fixed, and when it is worth buying a new one
The most commonly repaired parts are the power adapter, cable or connector, a dead diode group, the motion sensor, the buttons and the power board. Whether a repair pays off depends on the class of the lamp: it is usually worth repairing a professional lamp, while repairing a cheap model can cost almost as much as a new lamp. After the diagnosis we will tell you honestly.
If you decide to buy a new one, choose a hybrid UV/LED lamp with diodes on the sides as well, and compare power and features using the guide UV or LED lamp: which to choose. You can find all models in the UV/LED nail lamps section.
Lamp care: cleaning and storage
- After every client, wipe the base and inside of the lamp: drops of uncured gel on the diodes harden and become shadows.
- Do not cover the ventilation openings or place the lamp on a soft towel – overheated diodes age faster.
- Keep the cable loose and do not bend it at a sharp angle at the connector.
- Protect the lamp from drops and moisture.
- In the salon, compare curing with another lamp from time to time – that way you will notice the weakening before clients' coatings start to lift.
LED lamp repair: how it works
We repair UV/LED lamps from any manufacturer, regardless of where they were bought.
- Fill in the request on the repair page or call us. State the model and describe what is happening: flickering, switching off or not curing in a certain zone.
- Bring the lamp to the shop in Vilnius, Žemaitės g. 22, or send it by courier. Write to us before sending – we will send the address and advise how to pack it. Include the adapter and cable too.
- Diagnosis is free: we determine the cause and tell you the price. We do not carry out repairs without your consent.
- You collect the repaired lamp from the shop, or we send it back by courier.
Frequently asked questions
Why does gel polish stay sticky or not cure in the lamp?
If only a top coat with a tacky layer is sticky, that is normal – it is wiped off with a cleanser. If the whole coating is soft, the usual causes are a layer that is too thick, a cure time that is too short, a product not suited to the lamp, or weakened diodes. Check your lamp with the top coat test described above.
How long does an LED nail lamp last?
There is no single figure: it depends on the quality of the diodes, the cooling and how intensively it is used. LED diodes weaken gradually, so what matters more than the age of the lamp is whether it still cures in all zones.
Why is my nail lamp flickering?
Most often because of unstable power: an ageing adapter, power board, cable or connector. Some lamps pulse deliberately in low-heat mode, so check the instructions first.
Is it worth repairing a UV/LED lamp?
A professional lamp – usually yes, a cheap model – not always. Diagnosis with us is free, so first find out the fault and the repair price, and then decide.