A pair of fans sold as Sunon, bought offline

Let's start with the fact that I needed to buy a few fans and wanted something from a reputable brand. Today I want to tell you how it turned out.

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Let's start with the options for buying them.
1. AliExpress/Taobao and so on. Based on my previous orders, the result is almost predictable: the fans will probably be decent, but their actual specs will be lower than advertised—in other words, relabeled used fans.
2. Something new but unbranded is an option too, in principle, but I wanted something better.
3. The well-known Sunon fans at Kosmodrom, where I shop often, but the model that suited my main purpose cost about 204 UAH.
4. Look for the same Sunon fans at other stores.

I went with the last option, partly because other stores might have different models that aren't available at the Kosmodrom store I usually shop at.
And yes, my search led me to Prom.ua, where I first found a model that suited my needs, and then a second one for a different purpose.

I'll start with the second type: a small 40 mm fan, 10 mm thick. Kosmodrom had a suitable one, but I ordered one from Prom almost as an add-on to the order, though I can see now that this model isn't much more expensive.

Oh well, what's done is done. Anyway, I ordered four fans from the Radioformat store. The fans themselves cost me 520 UAH, plus almost 60 UAH for shipping. To be fair, the seller shipped the order as quickly as possible and declared it as documents, which made shipping cheaper. I placed the order during the day; it was shipped that afternoon, arrived at the parcel locker the next morning, and I picked it up that evening when we went out for a walk.
I ordered three 60×10 mm fans and one 40×10 mm fan.


I'll start with the small fan. I needed it to replace the fan in my RD6024 power supply, which I sometimes use to charge batteries after power outages. I really didn't like that it had started buzzing. Yes, the buzzing stopped once it warmed up. I took the fan apart and lubricated it, which helped a little, but didn't solve the problem. And I really didn't want to be left without my main charger, even though I always have something else I can use as a backup.


The fan is marked KD0504PFB1-8, rated for 5 V and 0.7 W, with a ball bearing.


It starts at 2.5 V and runs really well at 3 V; its power draw is even higher than the stated 0.7 W.


If you block the air outlet, the current barely changes. If you block the intake on the impeller side, it drops a little. This is typical of many fans: when you restrict the air intake, their efficiency drops significantly, which is why fans are usually designed to push air.



I'm removing the original fan from the RD6024 module. It's exactly the same size, although there are a few differences, most notably the shape of the impeller. The original was designed more to create pressure than airflow, but that's just my subjective opinion.


It starts at the same 2.5 V, but at 5 V its power draw is a little lower. It also makes more noise (buzzes), and it even seemed to blow harder.


If you block the air outlet, the current rises a little; if you block the intake, it drops noticeably. This fan is clearly designed to create pressure, and in that respect it's better than the new one, in my opinion.


Oh well, I can't leave the old one in there anyway, so I'll replace it. Though later I had the thought: what if I swapped the impellers...
I ran into two minor problems during the replacement.
1, 2. The holes in the old fan are recessed, but the new ones aren't, so I had to widen them a little with a 4 mm drill bit. The original holes are only slightly smaller in diameter, so I deepened them without using a drill or anything like that.
3, 4. This uses a different type of connector, but no big deal: a couple of touches with the soldering iron and we have the same connector.


Let's put it back in place. But before closing the case, I wanted to look into another problem: the new power supply was buzzing.
I noticed that the PSU buzzes while the module's output is inactive, but as soon as I turn it on, the buzzing stops. So it seems to be operating right on the edge.
I'd already installed a 2 kΩ resistor, but that didn't solve the problem. I tried adding another resistor in parallel. At 2.7 kΩ, a faint buzz remained; at 2.4 kΩ, it disappeared completely. And with the original 2 kΩ resistor, it buzzed so loudly that I could easily hear it from 5 meters away.
Anyway, I added a resistor, closed the case, switched it on, applied a load to make the fan start, and... silence. Much better than before :)



Now let's move on to the larger fans, the KD1206PFB1. I needed them as replacements in power supplies. Originally, I planned to show and test them in one of my upcoming reviews, but because of some circumstances I'll explain toward the end of the review, I decided to write about them now. So you could say this is an unscheduled review; I'll cover their intended use (if I do end up using them) another time.


The first thing I noticed was the label. It looks rather amateurish; the ones I bought at Kosmodrom had crisp, high-contrast printing.
Interestingly, this one has the connector I needed for the small fan, and the same connector I'll need for the project these fans were intended for.


They start at 2.6 V, which is surprisingly low for 12 V fans; usually they need more. There's practically no hysteresis, either—that is, the voltage needed to start them isn't higher than the voltage at which they stop working. The same goes for the previous fans.


The rated power was 1.9 W. The first test showed a little more, and at 15 V the fans drew about 3 W.
They move a decent amount of air.


Blocking the air outlet barely changes the power; it drops when you block the intake. But that's when I noticed something unusual.


The unusual thing was that the power consumption decreased over time. I don't remember seeing this before, or perhaps I just hadn't paid attention.
I took the second fan and powered it up. At first it drew about 2.2 W, but after roughly a minute it was closer to 1.9 W, and the downward trend continued.
I'll have to check the name-brand fans I have, but I've handled quite a few of them, and I think I would have noticed this by chance alone. Very strange.


The second thing I noticed was that it didn't have the characteristic feel of a fan with a ball bearing. Anyone who's ever compared sleeve-bearing fans with ball-bearing ones will know what I mean.
Ball bearings are much more reliable than sleeve bearings, which are essentially plain bearings, but they're also noisier and make a slightly more rumbling sound. This applies to the small fan too, though I didn't check it there.
I removed the label. Not only did it come off easily, but when I tried to stick it back on, it started peeling off again.

At first glance, the inside has a cheap sleeve bearing. Sunon fans have an odd feature: I don't know if it's true of the series listed in the specs, but the ones I've come across had no access to the bearing. If you needed to lubricate it, you'd have to drill a hole.


When you search for datasheets for this fan, you usually get one for the KD1206PFB1-8. They're very similar, but as far as I can tell, there are some differences.
At the very least, the impeller is different. The datasheet lists a ball bearing, by the way, but the rated power is 2 W.


I found a photo online of a fan with this marking, and yes, its impeller is completely different from mine.


Okay, I thought, and kept looking. I couldn't find a datasheet, but I did find a table of fans from this manufacturer, and it listed the exact KD1206PFB1, but with the H.G. suffix. Power: 1.4 W. A ball bearing is also specified, and the bearing type is actually included in the model marking:
V: Vapo B: 2 Ball S: Sleeve
In another series: V: Vapo, B: Ball
A third series also specifies whether it has one ball bearing (for slim models) or two (for wide models).



I even found a photo of a fan with this marking, and its power rating matches too.


But my fans have the MS.G suffix. I have no idea what it means; it could be anything, from the connector type to the wire length.
Another table lists the exact model KD1206PFB1 with the MS.G suffix, and again the power is 1.4 W, not 1.9 W, and it also has a ball bearing.


In a photo I found online, the fans are rated at 1.9 W, just like mine, but the impeller is different, and the fan housing itself looks different too.


After that, I simply gave up. It’s very difficult to make sense of all the types and generations of Sunon fans, even though datasheets do exist for them. Finding those datasheets can be quite difficult, though.

Let’s take the simpler route and look at the product page, which gives the model marking and manufacturer. The manufacturer is Sunon, and the marking indicates a ball bearing.


Now let’s look at the detailed description: it lists the same type and says twice that it has a ball bearing. What’s more, it says that, according to the official marking, the rotational speed is high. In other words, it emphasizes that the marking follows the manufacturer’s own system.


Let’s remove the impeller, in case they’ve hidden a ball bearing somewhere inside.
Nope, it’s the same sleeve bearing inside. The large amount of lubricant confirms it too; there shouldn’t be any in a ball-bearing fan.


This is what a ball bearing looks like in fans that actually have one. I think you can spot the difference with the naked eye.


But the sticker is an even clearer giveaway. Just compare the first one with the other three, which definitely came from genuine models. I could look for more at home, but unfortunately I don’t have a genuine one with the orange-red sticker.


Conclusions.
In my personal opinion, these fans aren’t Sunon, and in this case that’s outright deception of the buyer. Sure, someone might say, “Couldn’t you tell they were fake?” My answer: why should I have to spot anything? I see the brand name, the stated specifications, and two places saying it has a ball bearing. I buy it and pay with real, not counterfeit, money. I pay the price the seller asks, and get something that’s not much better than the fans I wanted to replace.
The second question is, couldn’t you tell from the price? Of course not. First, I have no idea where these fans came from, and I see no reason why they couldn’t be genuine at that price. Second, I showed earlier that there’s a definitely genuine 40 mm fan that costs just 15 UAH more, although it’s listed as having a sleeve bearing from the start.

If these had been non-genuine fans but still had ball bearings, I might have been able to accept that. But paying this much for a sleeve bearing of unknown quality just doesn’t seem right.
If I wanted to buy a cheap fan, it would have been much easier to go to the Elektronny Mir website and pick any model starting at 59 UAH. The one on the far right looks a lot like these “Sunons”—even the stamp on the impeller is the same.


I think everything I’ve said about the 60 mm fan applies just as much to the smaller one. I’m simply too lazy to take the power supply apart again, remove the fan, and open it up to check that it also has a sleeve bearing.

What do you think I should do in this situation? I’d really like to hear your opinion.
That’s all for today. I hope you found the article useful. As for my takeaway: if you want to buy genuine products, go to Kosmodrom or Radiomag.