Weird: Burning up Linksys routers

[jml1911a1]

Hello all,

I have a customer who has burnt up 2 Linksys WRT54G routers now, inside of three months. All my other clients' routers are doing just fine.

Here's the weird part: Her ISP is Comcast (cable), and before I installed her first router, she was having problems connecting to the internet. Comcast came out, and said it was a problem with her computer, that the computer somehow was "sending voltage back through" the ethernet cable.

I added an ethernet card (PCI; her original was on the motherboard), and installed a router at the same time. Less than two weeks later, the router died. I assumed a fluke, but now, just a couple months after that, the second router has kicked the bucket.

Has anyone ever heard of an ethernet card sending voltage back through the ethernet line (other than the normal operation)?

Thanks!

 

[bcastner]

I would suspect heat is the issue and not voltage problems. Do not lay the router on its side. Do not place anything above or below it.

A few things which cause grounding problems:
1. Grounding cheater plugs. (Those handy little 3 to 2 prong electrical outlet adapters) Used on equipment connected to the cable system , this will almost guarantee the appliance will use the cable as a ground.
2. Improperly wired outlets. (i.e.: Hot-Neutral wires reversed) Will cause hot chassis (current on ground) condition on A/V and computer equipment.
3. Polarized plugs, inserted backwards. These plugs are designed to be plugged in one-way for a reason, don't force them or modify them to fit in backwards.
4. Replacing 2-prong outlets with 3-prong outlets and not connecting a ground wire. Occurs mostly in older homes with handyman electricians around, causes a false sense of security and a very dangerous electrical problem.
5. Disconnecting or not having the coax cable ground. Illegal situation per the National Electric Code. Severe damage can occur to both cable company equipment and customer equipment if electrical surges occur. (Lightening, electrical line crossing cable lines, dropping a TV in a bathtub, etc...) Coax cable systems are grounded to prevent excess current from the customers home reaching the cable plant and to prevent excess current from the cable plant reaching the customer's home.

There shouldn't be more than 1 volt measurable between the coax cable and a known good ground.

How to check for grounding problems:
1. Check for the problems listed above. 90% of the time the reasons listed above are the causes for excess voltage on the coax cable system.
2. Use a electrical outlet tester.
3. Use a volt-meter or multi-meter, if you have proper instruction.

How to fix grounding problems:
1. Call you cable company to verify your house coax cable system is properly grounded. This should be done at no cost as it is required by law.
2. Call a certified electrician to verify proper grounding of your home electrical wiring and repair any problems found.
3. Remove any offending electrical equipment which is causing grounding problems.

Grounding problems, at their least, will cause intermittent or no connection on cable modems and poor or no picture on televisions. At their worst, grounding problems can lead to destruction of property and loss of life.

See the following link for interesting information on grounding issues and the problems they cause:
»

http://www.epanorama.net/documents/groundloop/

 

[jml1911a1]

OK, I'll check (or have client check) some of these.

Thanks!

 

[flapeyre]

Check the line voltage at the wall outlet.

Once, back when I serviced typewriters, I had a Selectric typewriter in an older building that went through three motors in as many days. The fist couple of times, I had thought it was the motor (and the replacement) being bad. The third time, I measured the voltage at the outlet and found 220 volts (it should have been 110). Somebody had replaced a 220 volt outlet (meant for a window air conditioner unit) with a 110 volt outlet, and they were plugging the typewriter into it.

I have a WRT54G, and it uses a transformer, so check the voltage coming out of there with a good voltmeter to make sure it's within limits. Are you using the transformer that came with the replacement unit, or just using the one that came with the original?

Feles mala! Cur cista non uteris? Stramentum novum in ea posui!

 

[jml1911a1]

Good thought, flapeyre. The outlet IS right under a window...

 

[flapeyre]

Also, I'm not sure it's the heat. I have the same model and it's sitting right on top of my DSL modem, which gets pretty warm.

Feles mala! Cur cista non uteris? Stramentum novum in ea posui!

 

[bcastner]

http://www.broadbandreports.com/faq/10011

 

[flapeyre]

Maybe for me it's because the modems are very close to an air duct, and when the A/C is on they get a nice cool blast of air.

Feles mala! Cur cista non uteris? Stramentum novum in ea posui!