the weirdest problem you've ever seen

Feb 07, 2005 3 Replies

Rate this thread:

Brian 21 years ago

Help! I'm at wits end here. This is a little long, but bear with me, it's a real gem. :-)

I'm using Comcast in Massachusetts and have a Toshiba PCX2200 cable modem. Last week, they upgraded us to 4Mbps. Since then, we've had a most unusual problem: the modem connection drops on sunny afternoons. To quote Dave Barry, I'm not making this up. :-)

If left untouched, the connection will stay dropped until late afternoon. On cloudy days, it works just fine. Now, where the cable comes into the house is on the south side, and when the sun begins to shine on that spot is about when the connection drops. Hmmm....

Here's what I've done.

1) Called Comcast. They sent a tech out to look at the problem. He found that we had too many splitters and a amplifier in the cable line to the modem, and he altered the cable wiring to get that out of the line. Of course, he came in the morning, when it was working. On the next sunny afternoon, it still went out.

2) Our cable modem is currently on the second floor, in our office. When the connection drops, I take my cable modem to the basement and plug it directly into the cable line coming in from the outside. When I do this, I get an immediate connection. I CAN THEN BRING THE MODEM BACK UPSTAIRS AND PLUG IT BACK INTO THE OFFICE, AND THE CONNECTION WILL CONTINUE TO WORK FOR SEVERAL HOURS.

I thought that maybe it was just the modem powering off for a bit that was doing the trick, but nope. If I just power it down, and leave it up in the office, it still doesn't work. I need to connect it in the basement and bring it back up.

Here's the modem diagnostics info: When connection is working: Received: -2.8 dBmV Transmitted: 40.7 dBmV SNR: 37.8 dB

When the connection is not: Received: -31.1 dBmV Transmitted: 8.0 dBmV SNR: 7.7 dB

I will gladly buy anyone a beer if you can help me. Thanks for listening.

Vote

$Bill 21 years ago

And make sure you're using at least RG6 cable.

Vote

Rick Merrill 21 years ago

Wag: your in-house cable is sub-standard. My 'cable guy' told me this and told me what to use and the upgrade made all the difference! You must use in-house the same type of cable that comes from the pole (more-or-less). You also must not have more than two splitters between you and the pole.

:-) How Quickly must you run upstairs?-)

Vote

Gary 21 years ago

What do you mean by "drops?" Does the "online" or similar light blink? Can you get any data through?

I suspect you have a lot of melt/freeze cycles going on this time of year. A random guess is that water is getting into the line when the sun creates enough melt water. Make sure all outside connections are clean, dry and tight.

If you can, on the next sunny day, install the cable modem in the basement in the morning. Let it run all day. See if it loose the connection. If it does, that will suggest an issue with your internal wiring. If it does loose the connection, that points to the outside wires. Bug Comcast some more in that case.

These look reasonable. Transmit power is a little on the high side, but not too high.

If the modem isn't connected, these are meaningless. If the "online" light is solid, these tell us the connection is bad. We already knew that...

You mentioned that the Comcast guy re-wired your house. In general, you want as few splitters as possible between the modem and the drop (drop=cable entry point). If you can, put a 2-way splitter right at the drop and use one leg of it to feed your modem while the rest feed your TVs/cable boxes.

-Gary

Vote