The laptop started humming all the time, even at idle: a steady whine that gets louder week by week. In our case the cause was not dust or overheating but the fan's bearing, where the oil had dried out.
Here is a real ASUS TUF Gaming repair: what is inside the fan, how to oil it without taking it apart, why WD-40 does not fix it and when a new fan is the simpler option.
Checked: 12.11.2026 · Applies to: ASUS fans 13NR00S0M09011 (CPU) and 13NR00S0M10011 (GPU), ASUS TUF Gaming FX505, FX506, FA506, FX705, FX706, FA706 laptops
What is inside the laptop
These models have two blower fans: one cools the CPU, the other the GPU. Each carries a sticker with an ASUS part number. That number, not the laptop model name, is what you search for when ordering a replacement.
| Sticker code | ASUS part number | Cools |
|---|---|---|
| FMLB | 13NR00S0M09011 | processor (CPU) |
| FMCA | 13NR00S0M10011 | graphics (GPU) |
Both fans run on 5 V and use a 4-pin connector. According to a spare-parts seller, the 13NR00S0M10011 GPU fan fits the FA506, FA706, FX505, FX506, FX705 and FX706. ASUS also made a different GPU fan for configurations with another graphics card (for example, 13NR00S0M12011), so check the part number on your own sticker before ordering.
How the fan works inside
The impeller sits on a steel shaft that turns in a sleeve bearing. It is not a ball bearing but a small tube of sintered metal powder whose pores are filled with oil at the factory. As the fan runs, the oil seeps to the surface and holds the shaft on a thin oil film.
There is not much oil in those pores, and over time it leaks out and dries up. Once it is gone, the shaft rubs against the bearing metal: first a hum, then wear. Fan makers describe this problem in their own patents.
A retaining ring at the very end of the shaft keeps it from sliding out. It is meant to be fitted once: pulled out, it bends and holds less firmly afterwards. On the back, the end of the bearing is covered by a round sticker with a plastic plug underneath.
In our laptop, once the sticker and plug were removed, there was a brown residue around the bearing: dried oil mixed with dust. The fan had run out of oil, and that was the hum.
Our mistake: leave the impeller on
With the bearing open, we decided to take the impeller off to clean the shaft. We pulled on it and broke several blades. The fan is very flat, so the blades are thin and long and have no strength to spare.
There was no need to remove the impeller at all: the oil could have gone in through the same hole under the sticker. If you really have to take it off, push on the shaft, not the blades. Lay the fan impeller-down so that the hub (the centre of the impeller) rests on a tube or socket and the blades hang free. Then push the shaft out straight along its axis with a thin rod through the hole at the back.
Do not use a heat gun: the impeller is held by the retaining ring, not glue, so heat will not help, and the thin blades may warp.
WD-40: why it goes quiet, and why not for long
A popular tip is to give the fan a shot of WD-40. It does go quiet almost immediately, and that is where most online videos end.
According to the official safety data sheet for WD-40 Multi-Use Product, 50 to 70 % of it is aliphatic hydrocarbons — a solvent — and less than 35 % is base oil. The solvent thins the old, thickened grease, so the hum goes away. Then it evaporates, leaving less oil in the bearing than it needs. In our experience, a fan "fixed" this way comes back in about a month, louder or stopped altogether.
WD-40 is sold as a multi-purpose product, lubricant included, but that mix is not suited to a bearing that has to hold oil in its pores for a long time. If you already have a can, use it only to flush the bearing: apply, let it drain and dry, then add proper oil.
Oil it or replace it
Oiling makes sense while the bearing is not worn: the impeller does not wobble sideways and the fan hums evenly, without rattling. If there is noticeable play or rattling, oil will only help briefly, and it is better to order a replacement straight away.
A replacement is not expensive. Prices we saw on 12.11.2026:
| Option | Price | Delivery |
|---|---|---|
| Ukrainian store, CPU fan | 370 UAH | in stock |
| Ukrainian store, GPU fan | 361 UAH | in stock |
| Ukrainian store, CPU + GPU pair | 695 UAH | in stock |
| AliExpress, CPU + GPU pair | 800.69 UAH + 156.98 UAH shipping | about two weeks |
It helps to accept that a fan like this is effectively disposable. The retaining ring is fitted once, the bearing is sealed under a sticker and a plug, and the blades have no strength to spare for disassembly. That is a deliberate trade-off for price and thickness: the fan is meant to be cheap and flat, not repairable. So oiling is a way to get quietly to a replacement, not a permanent repair.
Both fans had run for the same time, so we replaced the pair rather than one. The quality of non-original fans varies by batch, so test the new one right after fitting it, while the warranty still applies.
Do it yourself
⚠️ Before opening the laptop, shut it down and disconnect the battery cable from the motherboard.
Step 1. Check the fan
Remove the bottom cover and photograph the part-number sticker. Spin the impeller with a finger and gently rock it sideways. Play or a gritty feel when it turns means wear — in that case order a replacement straight away.
Step 2. Open the bearing and oil it
- Undo the fan screws, unplug its connector and lift the fan out: the bearing is reached from the side facing the keyboard.
- Peel off the round sticker in the centre of the back.
- If the bearing end is closed by a plastic plug, pierce or pick it open with an awl or needle. ⚠️ Do not drill: shavings will get into the bearing, and the driver board is right next to it.
- Clear out the bits with tweezers and a cotton swab dipped in alcohol.
- Add one or two drops of light oil for small mechanisms — sewing-machine oil or silicone oil. Spin the impeller and let the oil soak in for 10–15 minutes.
- ⚠️ Do not remove the impeller.
Step 3. Seal it and test
Wipe off the excess oil and cover the hole with a tight sticker — Kapton or aluminium tape — so the oil stays in and dust stays out. Reassemble the laptop and test it under load, in a game or a stress test. HWiNFO is a convenient way to watch temperatures and fan speeds.
If the hum is back within a few days, the bearing is worn and oil will not help; replacement is the only option left. Do not keep re-oiling the same fan over and over: every teardown adds the risk of breaking a case clip or a ribbon cable.
When to call a technician
If the fan already rattles or has play, or you are not sure you can put the laptop back together without breaking clips and ribbon cables, hand it over for servicing. For an office with several laptops, scheduled maintenance pays off: cleaning, fresh thermal paste and a fan check before the machines start overheating in the middle of the workday.
IT Outsourcing — on-site in Odesa and remote support across Ukraine.
FAQ
Can I oil the fan without removing it?
Not on these models. The sticker that gives access to the bearing is on the side facing the keyboard, so the fan has to be unscrewed.
What oil should I use?
Light oil for small mechanisms: sewing-machine oil or silicone oil. WD-40 as a lubricant, vegetable oil and thick greases are not suitable.
Can a broken blade be glued back?
No. Even a small missing piece throws the impeller off balance: the fan vibrates, gets noisy and wears out its bearing faster. A fan like that gets replaced.
Sources
- IPC-Computer — ASUS fan 13NR00S0M09011 (CPU)
- IPC-Computer — ASUS fan 13NR00S0M10011 (GPU)
- AIO.lv — compatibility of the ASUS 13NR00S0M10011 fan
- Sparepartworld — ASUS fan 13NR00S0M12011 (GPU, GTX 1060 configuration)
- WD-40 Company — WD-40 Multi-Use Product safety data sheet (SDS)
- USPTO — US patent 8083480 "Cooling fan", on oil-impregnated sleeve bearings
- Our own teardown photos; store prices as of 12.11.2026
