F5F Stay Refreshed Power Users Networks Issue with FS728TPv2 fan replacement Problem with swapping fans in FS728TPv2

Issue with FS728TPv2 fan replacement Problem with swapping fans in FS728TPv2

Issue with FS728TPv2 fan replacement Problem with swapping fans in FS728TPv2

6
66babou
Junior Member
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48
03-07-2022, 11:22 AM
#1
you need a lot of assistance here. you're using a netgear fs728tpv2 poe unit that makes a loud jet sound, so you switched the fans to 40mm noctua nf-a4x20 flx models. the old fans run at 12v and the new ones at 6v to 13.3v. when the noctua is on, it handles between 4.8v and 13.3v. you noticed the new fans spin up at startup but stop after a few seconds. i checked the voltage and it reads 4.8v, which matches the old range. as the switch heats, will the voltage rise? that’s good. it’s normal for the fan speed to adjust with temperature. make sure the pinout matches what you have.
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6
66babou
03-07-2022, 11:22 AM #1

you need a lot of assistance here. you're using a netgear fs728tpv2 poe unit that makes a loud jet sound, so you switched the fans to 40mm noctua nf-a4x20 flx models. the old fans run at 12v and the new ones at 6v to 13.3v. when the noctua is on, it handles between 4.8v and 13.3v. you noticed the new fans spin up at startup but stop after a few seconds. i checked the voltage and it reads 4.8v, which matches the old range. as the switch heats, will the voltage rise? that’s good. it’s normal for the fan speed to adjust with temperature. make sure the pinout matches what you have.

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T
Tweet_Tee
Junior Member
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46
03-08-2022, 05:08 AM
#2
The Noctua enthusiasts I've collaborated with mostly (NF-F12 models) have a voltage cutoff that halts their rotation once they drop below a specific level. In my tests this behaves more like a safety switch—it won't restart if you increase the voltage. To clear it, you need to disconnect and then reconnect power. I’m unsure if the 40mm ones are identical, but it’s probably the same.
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T
Tweet_Tee
03-08-2022, 05:08 AM #2

The Noctua enthusiasts I've collaborated with mostly (NF-F12 models) have a voltage cutoff that halts their rotation once they drop below a specific level. In my tests this behaves more like a safety switch—it won't restart if you increase the voltage. To clear it, you need to disconnect and then reconnect power. I’m unsure if the 40mm ones are identical, but it’s probably the same.

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