Cable modem question

[Input Nirvana]

I bought a Motorola SB6141 cable modem 6 months ago. It's started to make clicking noises when downloading/uploading (internet activity) Sounds like an hdd read/write. I didn't notice the noise previously, but I moved a month ago, have the same internet service, and only moved to a different residence about 80 feet away. Everything else is the same. I think I'm getting 50mb down/12mb up, so I'm not complaining about that, but the noise is odd.

What is it and why didi it start now?

[tp4tissue]

If there is a fan, then it's the fan bearings getting loose from the heat stress, these things are quite warm internally.

If the noise is high pitched, then it's probably inductors or "certain" ceramic caps which vibrate. These pieces are usually held down with rubbery goop, or rubber housing, so over time, the heat makes them ineffective at muffling the vibration.

[Trent]

I bought a Motorola SB6141 cable modem 6 months ago. It's started to make clicking noises when downloading/uploading (internet activity) Sounds like an hdd read/write. I didn't notice the noise previously, but I moved a month ago, have the same internet service, and only moved to a different residence about 80 feet away. Everything else is the same. I think I'm getting 50mb down/12mb up, so I'm not complaining about that, but the noise is odd.

What is it and why didi it start now?

Capacitors can make strange clicking/whirring noises when they start to die.  The unit will probably go in a couple of weeks is my guess.

Does it sound like this?

[Leslieann]

It's electrical switching of some sort, it may be fine it may not be
Try a different power pack or outlet.

I'd be worried it may be hurting the computers it's connected to (due to noise).

[Input Nirvana]

Don't think there's any fan, it's dead silent, can't feel/hear any air movement or gyration.

Did a bunch of web searches, comes up nothing. Only one allen head screw to open it up...doesn't look right but maybe I'll see what's up in that bad boy to isolate what is making sound.

When I do a speed test, it sounds like an HDD reading/writing.

[Trent]

I'd be worried it may be hurting the computers it's connected to (due to noise).

Sorry, no.  The only thing that is going to get damaged in all of this is the modem itself.

[Input Nirvana]

It's just a CAT 5E ethernet cable connecting the modem to my Airport Extreme, not pure power. So I imagine it's relatively safe.

Not sure what to do. Interesting and annoying.

[Leslieann]

I'm not worried about a power surge (though highly improbably, but not impossible), I was more worried about RF noise being sent down the line.

Just because there is no power through the lines doesn't mean it can't harm the computer or router. I have seen some very strange things happen with network cards (computers reset, killed... etc...).

[smknjoe]

I have the 6121 and there is no HD or fan. Probably a bad cap like the other guys said. Is it possible you have some other electronic device close by that's making the noise instead?

[Input Nirvana]

I have the 6121 and there is no HD or fan. Probably a bad cap like the other guys said. Is it possible you have some other electronic device close by that's making the noise instead?

It's coming from the cable modem, that's confirmed. It only happens when loading new info. For instance, I load a new image page and hear a little click-click, if it's more data, it clicks more. During a speed test it clicks the entire upload/download and sounds like rain. If I just randomly click pages
that are mostly cached, I don't hear anything. Does that seem right?

[PointyFox]

I have the 6121 and there is no HD or fan. Probably a bad cap like the other guys said. Is it possible you have some other electronic device close by that's making the noise instead?

It's coming from the cable modem, that's confirmed. It only happens when loading new info. For instance, I load a new image page and hear a little click-click, if it's more data, it clicks more. During a speed test it clicks the entire upload/download and sounds like rain. If I just randomly click pages
that are mostly cached, I don't hear anything. Does that seem right?

So, you are not wearing headphones and have the computer sound muted and any amplified speakers turned off?

[Input Nirvana]

I hold up the modem to my ear and it's plainly coming from the modem. It's interesting...sounds almost like it's supposed to do it. LOL

I wonder if it's something I can replace?

[PointyFox]

The only things I can think of is bad capacitor or you're hearing EMI over the computer's audio system.

[smknjoe]

I've never heard of such a thing from a solid state device. Sounds like a bad component but it's hard to tell and probably not worth investigating (by testing the components) or repairing. I would use it until it dies or get a new one sooner if you can live with the noise.

Maybe try repositioning it to see if that helps?

[smknjoe]

or you're hearing EMI over the computer's audio system.

That too.

[Input Nirvana]

Sound is absolutely from cable modem. No doubt what so ever.

It's very pronounced, (HDD reading/writing), I can live with it. Definitely not worth monkeying around with, get another for $70. Annoying it's only 6 months old.

[Trent]

I'm not worried about a power surge (though highly improbably, but not impossible), I was more worried about RF noise being sent down the line.

Just because there is no power through the lines doesn't mean it can't harm the computer or router. I have seen some very strange things happen with network cards (computers reset, killed... etc...).

Really?  That's new to me.  I'd think the grounding on the laptop/desktop would be sufficient to prevent this...

[PointyFox]

Where is the sound coming from?  From inside the router?  From speakers?  From headphones?

[Input Nirvana]

The clicking comes from inside the cable modem itself. There is no vibration while it clicks, just the noise only.

[smknjoe]

Sound is absolutely from cable modem. No doubt what so ever.

It's very pronounced, (HDD reading/writing), I can live with it. Definitely not worth monkeying around with, get another for $70. Annoying it's only 6 months old.

Maybe try resetting it (power cycle) or contact your ISP to see if they can test it from their end. Here are the specs for the device. I don't see a HD and have never heard of one in a consumer modem. http://moto.arrisi.com/staticfiles/Video-Solutions/Products/Voice-and-Data-CPE/DOCSIS-Modems-Gateways-and-eMTAs/Cable-Modems/SB6141/_Documents/_Static_files/SB6141-US-EN.pdf

You could get another one and if it works send the bad one back under warranty. That's about all I have for you, man.

When you run a speed test at speakeasy.net/speedtest what does it show for line quality?

[PointyFox]

Could be a power transformer inside vibrating too; but those tend to hum.

[Input Nirvana]

I did the power cycle. No change.

I will call or chat with Comcast and see if they can check/ the modem.

I did the speediest, the clicking is mostly on the upload portion. The quality of the line was not shown, I believe I need to download a Java applet, not sure which/what...it takes me to Oracle's site. I have a Mac.

[Input Nirvana]

I'm streaming Hulu video and the modem is not clicking. I don't understand. Maybe it's mostly happening on upload? When you surf the web there's info that goes both ways when you access pages.

[smknjoe]

Here's the advanced test http://www.megapath.com/speedtestplus/

[Leslieann]

Really?  That's new to me.  I'd think the grounding on the laptop/desktop would be sufficient to prevent this...

Grounding does nothing for noise.

[tp4tissue]

Really?  That's new to me.  I'd think the grounding on the laptop/desktop would be sufficient to prevent this...

Grounding does nothing for noise.

for rf noise it does if the case is metal I thought.

[PointyFox]

Really?  That's new to me.  I'd think the grounding on the laptop/desktop would be sufficient to prevent this...

Grounding does nothing for noise.

for rf noise it does if the case is metal I thought.

Grounding helps.  Also metal cases help reduce EMI. 
https://en.wikipedia.org/wiki/Faraday_cage

[Trent]

Really?  That's new to me.  I'd think the grounding on the laptop/desktop would be sufficient to prevent this...

Grounding does nothing for noise.

Well noise as in sound yes, but I assume you're talking about digital noise right?

[Leslieann]

Grounding helps.  Also metal cases help reduce EMI. 

The case acts as a simple Faraday Cage, grounded or not, the metal blocks the signals.

You don't even need metal for some frequencies, water blocks GPS frequencies, trees and leaves will do it. Water also blocks wifi.

Well noise as in sound yes, but I assume you're talking about digital noise right?

There can be RF noise, crosstalk, stray voltage...
I have seen it shut down computers and destroy nics. It's rare, but it happens.

A common point of failure in routers and modems is cheap capacitors, particularly if you live in the midwest where they have sh*tty power regulation. If a capacitor goes, there is no telling what kind of power spikes it can send down the line. It doesn't help that China stole an incomplete capacitor formula (10 years ago and are still using them), or often make substandard parts to begin with, but then you have modem and router manufacturers who under spec the power packs on these same modems and routers which only further stresses the components. Some routers are so under powered, that the power pack doesn't even supply enough power for the chipset alone, much less the rest of the circuit board or usb port. This isn't oddball unknown companies either, one very popular router was underspec'd this way when it was released, and another hugely selling (pile of garbage) from another well known manufacturer has been selling this way for years.

In many offices I work in, the owners buy cheap routers, which often are replaced every 1 to 2 years (when they become unstable). Even high end home routers only manage about 3 years under the terrible power regulation we have. I run most of my infrastructure behind a UPS (Uninterupted power supply) that contains  battery backup/lightening protection/filtering/power regulation in order to make the parts last longer and run better. I found years ago that not only did parts last longer and run more stable, even in places with good regulation, but also that I could overclock higher since my power was more stable.

Getting back to this modem, it clearly has a problem, the only question is what it's currently doing, how long before it dies, and what will it do to things connected to it when it does.

[Input Nirvana]

Stuuu-pit cheeeep a$$$ electronics!!!!

Thanks for the accurate industry rundown on shizzzy shizz-shizz. I now have less faith than ever before. I haven't run a UPS/power conditioner in 5 years. Maybe I should go that route again. I'm sure it won't raise my electric bill much and there should be several benefits.

My poor router I suppose I should document his decline and eventual impending death, try to make him as comfortable as possible while living his abbreviated life to it's fullest. I was such a proud papa bringing him home and unbundling him into the family. I'm sooo sad,

...Surfboard 6141, we hardly knew ya

[Leslieann]

I honestly think you probably just got a dud. Surfboards are some of the most reliable cable modems. It's what I use, not sure if mine is higher or lower end though and it's been flawless.

Scarily enough, California power regulation is actually FAR better than the midwest. Seriously, MUCH better. I go through lightbulbs at 3 times what I did in Southern California. However, I still benefited from power regulating ups systems. In fact it was there that I discovered how helpful it was. I see a ton of dead electronics here, and I'm totally convinced it's all the power regulation.

An Ups will likely cost you no more than $10 a year in power. Most of the time they do little more than pass electricity and keep the battery topped off, so it's not using much unless it's been drained.