Modem/Phone noise problem

[#1]

Hi,
My dear old mum signed up with Plus Net about 5 weeks or so ago. Since the broadband was activated, her phone line has excessive noise, but only when the modem is connected to the line. I have disconnected all the extensions and connected three different microfilters directly into the test port of the BT master socket. The line is OK untill the Modem is plugged into the filter, then the noise starts and you can distinctly hear the modem's high pitched squeals. I have also tried with a different modem, but the problem is still there. I ran a line check from the BT website, but that reported no faults...can anyone please offer any help or advice???
Thanks,
Martin

[#2]

The high frequency squeals, as well as hissing, or crackling, should be filtered out by the ADSL filter.  This is indicative of poor quality filter(s).  I guess it could as well be a problem with the modem, but unless you were to replace that with a knowingly good example (from a friend?) you wouldn't be able to isolate the problem.
--
Regards,
Mick

[#3]

What make & model of broadband modem is it? Did PlusNet supply it?

[#4]

From an experience point of view, you have done the needed testing and we should raise this as a Broadband fault for you.
To get the complexities out the way, I would suggest the following as mop-up before we proceed with that though.
With the alternate modem and filters in hand, along with your phone, unscrew the front plate of the master socket. Plug the filter into the test socket exposed and alternate around the modem and filters available.
If the noise is still happening, it's safe to assume there is nothing you can do otherwise.
We will advise you as part of the faults process the standard advise about charges which may apply if proven to be internal cabling, filters or equipment, which comes in at a not so nice £169.20 (£144+vat).
It's standard advise and aside from the encouragement to ensure the checks are done, these are costs we have to pay on your behalf for engineers time. The above testing disproves this.

[#5]

I have tried with three different makes of Microfilter, one of them a D-Link (not sure what make the others are). The modems ( I have tried with two) are both D-Link one is a DSL G624T (this is my own modem which works fine at my house, but again gives this noise problem on my mothers line) and the other a DSL G604T.  Neither were supplied with Plus Net, but as I said, they both work fine on the my line at home as do the microfilters.

[#6]

Just a thought.... have you tried a different phone? It could actually be a faulty phone.