6300 fan noise - should I worry?

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  • Updated 4 months ago
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My Flex 6300 runs 24x7 to enable remote operation. The radio lives in a clean, but not temperature controlled, garage environment in Texas. I had no problems with heat in summer or cold this fall, but several days ago I noticed my radio was unavailable via SmartSDR/SSDR for iOS, so I checked out the radio in person at remote location.


Powered up radio, green light flashed on and off, and then made a horrible racket. After about a minute, the radio 'clicked', then powered down. It did this several times over the next 15 minutes, never once staying 'on'.

Since I didn't have proper tools at remote location, boxed up the radio and brought it home.

Put radio on the bench, connected it to 13.8v, radio again turned on, but made loud fan noises... this time though it stayed on, the flashing green light stayed on, an the radio seemed fine.

I opened the case to clean the fans, they were all clean. Hooked up power with the lid off, radio powered up and stayed up.

Put cover back on the radio, pushed in the power switch, and the fans were quiet. Not silent, not clanging, but reasonably quiet and the radio came up and stayed up.


So my question: should I be worried about future fan failure? Could it be a thermal thing? The inside of the radio is pristine, so I don't think it's a dirty fan problem.

Any ideas/advice?


Ken, N2VIP
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Ken Hansen

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Posted 4 months ago

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Bill -VA3WTB

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Were you able to tell just witch fan made noise? Even if the fans are clean the bushing in the motor could be on their way out. Ken, you can service the fans buy taking the seal off the center and putting a small drop of 3and1 oil in the bushing. This may give extra life to the fans.
Keep an ear out to them. If the fans slow down too much the radio will shut down even before the temp goes up to high.
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Ross - K9COX

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Good question, my 6500 is over 3 years old and shortly after I got it the fan made a terrible noise and the radio faulted out. After several power cycles it went away and has never returned.
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Brian Morgan VK7RR/4

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As usual Bill makes a lot of sense with his thoughtful answer. But I would like to take it a bit further. I will talk of the 6500. It has 4 fans and it is difficult to tell which of them is on the way out. Two fans are on the sides of the radio and easily accessible. To identify which fan or fans need replacing, get a stethoscope or an insensitive microphone and put it near each fan in turn, recording what the mic. picks up. It becomes quickly evident which needs replacing. If it is the side fans they are easily replaced. I can't speak of the internal ones. My suggestion is that you find the noisy one or ones and replace both.  If one is going, it is only a matter of time and the other will follow. Operating it remote it is better to be safe than have the radio turn itself off again due to insufficient air being generated. I operate my 6500 remote and now use a wifi switch to turn it on when I want to use it, rather than leaving it turned on all the time.
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Danny K5CG

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Hi Ken, you'll find another thread on this forum about this exact issue on the 6300, complete with pictures.

Glad to see another Flex owner in the RWK too!
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Bill -VA3WTB

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Ken, the reason I mentioned possibly servicing the fans is because the small fans inside the shield are no longer available anywhere. If it is a side fan, you can find an exact replacement on line.
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Al / NN4ZZ

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Hi Bill and Ken,
Eric just posted on the community 3 weeks ago about placing another order for the small 50MM fans.  

Ken, here are some notes, pics and video about replacing the fans on my web page:


Regards, Al / NN4ZZ  
al (at) nn4zz (dot) com

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Brian VK3MI

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Hi Ken

I think you should be worried. I had a Flex-6300 with similar symptoms that gradually got worse over time and eventually resulted in the radio failing to boot up on a regular basis. FlexRadio will fit new fans in this situation - see https://community.flexradio.com/flexradio/topics/flex-6xxx-fan-replacement

73, Brian VK3MI