It's not a phone line problem as we ran test with line filters and meters and the line was not the problem.

Here's what we noticed.

At about 75%+ humidity our modem starts the scratching noise and cant connect at all.

If the humidity is around or below 40% it starts doing it again.

We tried this in 3 different computer from cyrix to Pentium 200mmx to Amd Duron 800+ MHz systems and 2 seperate 5610a modems.

Throw the modem into the snow.

I had pretty much given up on using this modem and went back to my old Lucent LT. But, after re-reading these posts, and seeing that some folks were able to get the modem running again via RF filtering on the phone line, I wanted to see if a RF filter would work for me also.

Well -- I picked up the $11 RF telephone filter from Radio Shack and installed it on my line. While it did not 100% cure the issue for me, I noticed that the static/screech effect happened less often. I also noted that, like many people here have, the problem would ONLY occur at night.

Putting these facts together, I figured something that I ran at night was putting out a lot of RF in my house that was interefering with my modem. Last night, I noticed the static sound again -- and I carefully too note of all the appliances that I had running. I then turned them off one-by-one until I had determined the culprit.

It was my dimmer switch for my lights in the kitchen.
A little research on the net confirmed that dimmer switches can put out a lot of RFI. Switching the thing off allowed my modem to connect. Full-on (no limitation in current) also did not generate RF. But if the dimmer was limiting current, it would hose the modem.

I suspect those of you that had ceiling fans might also have dimmer switches on them to control speed and/or light output. Please check. For those of you in apartments, if could even be your neighbor's dimmer switch(s) that are giving you grief! Read the following FAQ from Lutron corp, look down the page to the part discussing RF:

http://www.lutron.com/product_technical/faq.html

There are two types of RFI, radiated and conducted.

Therefore the modem could be getting too much RFI through the air, or even the AC power lines, even though I run through an APC UPS and a surge suppressor. The FAQ suggests the following to eliminate/reduce RFI from your offending dimmer switch(s):

There seems to be a set of recurring themes in this
3cp324510abanshee debate.

#1: Weather/atmosphere definitly seems to affect the modem, either by static or my too much humidity.

As these modems do not use the standard RELAYs to pick up the phone line (they use a solid state trigger).With solid state circuits there is the increased possibility of
static or humidity interfearing with the modems line connection.

#2: EMF (Electro Magnetic Flux). Translation: Dynamic and
stronger than usual Changes in the surounding Electrical and Magnetic fields. This includes ex. fans (ventilators).
Remember in movies when people in the next apartment ran a blender and it realy messed up the persons tv? Well this is
indeed true and computers are indeed even more suceptable.

There is another of the main problems as well. A few years back there was also a term called "buss noise" in sound cards, which when recording or playing back you could hearthe computers natural beeps, clicks and wheezes though the sound card.

A remedie for this was to place the sound card or modem in the ISA or PCI slot closest to the top or closest slot to the computers power supply bypassing the remaining busses. Also making certain that the modem or sound card was properly grounded.

#3: Line noise . This is by far one of the most disputed
of problems.. The funny this is that most that have a spare 56kb modem state that they get no banshee screech from ex.
a conextant, or gvc, or diamond, e.t.c. They also attained
approx the same speed (or better) as the USR modems .

We've tried a phone share device, which basicaly isolated the main connecting item such as a modem and routes it directly to the outgoing phone line via a thickly shielded
RJ54 cable with a rj11 converter on the end.

This did make a small improovement (very small infact: a 1.37% improovement).

Here's a bit of fact USR made another blunder.

When we researched the 3cp325610 modem it was calssfied as
HCF (hardware configure). Which refers to physicaly changing jumpers on teh modem itself to set the IRQ and ports addresses.

This modem has no jumpers. It's a controler modem , and not
a winmodem (aka: software modem).

But who in thier right mind would set a modem to auto install on COM5: IRQ 12.

USR's own dosmdm.exe can't set IRQ 12 in dos..

Also notice that most Linux OS's won't take the modem.

Apart for debian, and Red Hat it's almost impossible to get this 5610a/b modem to work.

Oh yes so far to date I've never had the modem banshee screech on me in Linux. However that does not mean anything.

Thanks for listening

yt

Curious

I flash upgraded the above modem to V92. All went well in the upgrade. the modem connects much quicker to my ISP.

Problem:
When i try to connect the modem goes to the handshake and then emits a high pitched squeal and it will not connect.

I just cancel and try connect again. The modem then connects properly. However I sometimes have to try and try again to get it to handshake properly. USR seem to not have a clue what the problem is.

Help