1. Home
  2. Electronics Repair
  3. Netgear CG814WG v2 cable modem blinking lights.

Netgear CG814WG v2 cable modem blinking lights.

I have a Netgear CG814WG v2 cable modem. The internet went out this morning and I checked the lights on the modem. The power light comes on, then the connected ports light up, then all the lights on the modem go on, then they all go off. This cycle repeats continuously. I held down the reset button for 10 seconds but that didn't clear up the problem. I thought it was weird that even though I was holding down the reset button, the lights continued to cycle on and off just like before.

In my efforts to narrow down the problem, I have the following question. Shouldn't the lights remain steady even if there is nothing hooked up to the ethernet ports on the modem? I called the cable company and the tech agreed with me and said he never heard of that happening before (all the lights cycling through an on/off pattern). I left it powered off for a few hours and powered it back on, same thing.

Thanks for your reply.

--
David Farber 
Los Osos, CA
Reply to
David Farber
Loading thread data ...

I'm reminded of the old riddle "What time is it when a clock strikes 13?" -- "Time to get a new clock."

In general, none of the router output lights should be illuminated unless the output is actually connected to computer. The symptoms you describe suggest a bad router.

Reply to
William Sommerwerck

--

the

st a

You power cycled it, that's about the most you can so, take it back to your cable company and get a replacement. If necessary, demonstrate to them that it's dead at their office. Mention that you have been without service for X days and want a refund on the internet portion of your cable bill.

Reply to
hrhofmann

Kinda sounds like continuous reboot or a diagnostic display.

Unplug the coax cable to the CATV network, and try powering on again. If the flashing lights symptoms are identical, it POSSIBLY means that you've lost the connection to the CMTS (cable modem termination system).

Dunno. Maybe it's in the manual: or a bit of Googling:

I've seen that, but on an Arris VoIP cable modem. One of the phone ports had a cable installed that was chewed by a rat and shorted. To indicate that something was wrong, the front panel lights produced a light show of diagnostic flashing lights that were eventually decoded by extensive Googling. I never did find any documentation on what the flashing lights meant and had to rely on anecdotal guesswork. This may be more of the same. Unplug everything except the coax cable and try again.

You might also try asking in the support forum for your cable internet service provider.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

Hi Jeff and everyone else who posted before,

The first thing I tested was the power supply. It read a steady 5 volts dc. I tried every type of reset. It didn't help. It is now more than 12 hours since the problem happened. Then it dawned on me, what does the output sticker on the power supply say? Really? *12* volts dc? I couldn't find another 12V 1A wall adapter in my box of power adapters. But I do have a 12V portable jump start car battery with a built in air compressor AND a dc output jack. I rummaged through my stuff again and found a car cigarette lighter (do we still call them cigarette lighters?) attachment with a standard small plug on the other end. I hooked it all up and now it's working again. My next question is until I find a suitable AC adapter replacement, can I just keep this 3-in-1 jump starter plugged into the AC all the time to keep it charged? This is what it looks like though I got it from Costco many years ago

formatting link

Thanks for your reply.

--
David Farber 
Los Osos, CA
Reply to
David Farber

he

on

ued

o
s

rs

e

pe_highlighting 831-336-2558 FREE

c.

12V

it

air-compressor-8884.html

If you have two 5V adapters, you might be able to put the two outputs in series to get 10V. That might be enuf to power the electronics, they are somewhat tolerant of lower input voltages. Can't hurt to try since you already know 5V didn't harm anything.

Reply to
hrhofmann

Interesting suggestion. I think I will try popping the case open on the original one and see if there are some dried out caps. Any suggestions on how to get a screwdriver into the seam of the case and prying it open without destroying the whole thing? On the other hand, I just found this on eBay.

formatting link

Thanks for your reply.

--
David Farber 
Los Osos, CA
Reply to
David Farber

Did you test it with a load? Open circuit testing doesn't show much. Extra credit for using an oscilloscope to check for noise and hash on the output.

I've had some problems with Netgear rebranded power supplies: Caveat emptor.

The replacement supply you found on eBay is 5VDC 1A which won't work. The correct adapter is 12VDC 1.5A.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

Hi Jeff,

Wow. I must have that 5 volt number stuck in my head. Thanks for pointing that out. Must be the stress from not having internet for more than half a day!

You can dock me points for not using a scope and then more points, make that dollars, when I almost ordered the wrong power supply. Why would I need to test it with a load when it's already less than half the voltage it's supposed to be? This was one of those situations where I did a quick memory scan of everything I had ever fixed. Replacing a power adapter that had a low output (not including ones that were totally dead) wasn't on the list. Anyway, I found an online video on how to crack these things open. A small butter knife and a rubber mallet to strike the knife along the seam of the case popped it right open. It took only a few minutes to find the bad cap.

470uf @ 25 volts. I had a 35 volt one in my box and it just barely fit into the case. I powered it up and it works fine now.

Thanks for your reply.

--
David Farber 
Los Osos, CA
Reply to
David Farber

In this case, there's no need for the load test. However, I've seen power supplies that appear to produce the rated voltage, that produce something quite different if loaded with a resistor. This is especially true if the output filter caps are only partially defective.

I use a putty knife. Squeezing the case in a padded bench vise also works.

Congrats. I have a capacitor ESR tester to check the other caps. That's about a 3 month collection of bad caps. While many are visibly defective due to a bulging top, many were not and only the ESR tester showed a problem.

--
Jeff Liebermann     jeffl@cruzio.com 
150 Felker St #D    http://www.LearnByDestroying.com 
Santa Cruz CA 95060 http://802.11junk.com 
Skype: JeffLiebermann     AE6KS    831-336-2558
Reply to
Jeff Liebermann

3 months of bad caps or one, ok maybe two, old Mitsubishi TV's. (-;

The ESR meter is what I used to find the culprit. The other caps seemed to be in the normal range.

Thanks for your reply.

--
David Farber 
Los Osos, CA
Reply to
David Farber

Flatbed scanners use a 12V 1.25 or 1.5 A power supply, and are often floating around in piles of electonic junk.

Reply to
Michael A. Terrell

dc.

rs

a 12V

e

AC

t it

en

This whole interchnge of e-mails just shows how importannt little things turn out to be.

Reply to
hrhofmann

Exactly!

Thanks for your reply.

--
David Farber 
Los Osos, CA
Reply to
David Farber

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.