Mediocre broadband performance fallen off a cliff

[#1]

I've been away for a week and come back to find instead of connecting at ~5Mb down with 6db noise I'm getting:

ADSL Link	Downstream	Upstream
Connection Speed	2535 kbps	965 kbps
Line Attenuation	49.5 db	29.1 db
Noise Margin	0.3 db	6.0 db

This is after manipulating the router into sacrificing downstream speed for a better SNR but it's still virtually unusable, almost every webpage needs reloading a handful of times before enough of it will load to read anything. Any suggestions (beyond the usual unplug everything, try a different micro filter, I don't have a spare router...) or do I just need to report a line fault?

[#2]

Have you tried a quiet line test (17070 Option 2) using a corded phone? Is there any noise on the line and if so is it still present with the phone plugged into the test socket via a filter and the router disconnected? If noise is present that needs to be reported to your phone service provider as a voice fault.
Has anything been done to your internal network since you last used it? Sky box disconnected and reconnected without a filter?
Otherwise I suggest submitting a fault using the troubleshooter at http://faults.plus.net. Since you don't have a spare router you can only reply 'no' to the question concerning trying one and press on. Plusnet should get back to you if their tests suggest the router could be at fault.

[#3]

Thanks. Curiously the quiet line test has always been reasonably quiet, certainly no clicking or anything like that, but on a voice call it's often so noisy you can barely hear the other person.
Literally nothing changed in the last week as there was no one in the house, but I can't think of anything changing in the last 6 months even. There's no Sky box and only one master phone connected, which I've tried disconnecting. Also tried a different microfilter without success.
Guess I'll push on past the option saying I could be charged if there's a fault with my equipment then... ack!
Sync speed is down at 1536 kbps now and falling each time it disconnects and reconnects. Oh, and there's no test socket - I've had a BT engineer confirm that oddity before, although quite why he didn't then fit one now escapes me.

[#4]

Quote from: richandsian

Curiously the quiet line test has always been reasonably quiet, certainly no clicking or anything like that, but on a voice call it's often so noisy you can barely hear the other person.

Is that noise problem with a corded phone? Identifying the cause and eliminating would seem to be worthwhile - when it occurs does it last long enough to disconnect the router from Plusnet using its web interface, then switch  it off? (To eliminate the router as the cause.) That problem would need reporting as a voice fault to your phone service provider.
As you are doing I think reporting a fault at http://faults.plus.net is the right thing to do. Since you don't have a test socket all you can do is use the master socket and unplug everything else. Just give the best answer you can to the questions.

[#5]

PlusNet (owned by BT) have come back to say there's a suspected earth contact fault on the line and I need to contact my phone provider to sort it (BT).
Left hand / right hand?! 

[#6]

Run as separate companies.

[#7]

What did BT say when you phoned them? Were they able to give you an estimate when they'll fix the fault. I recently had an earth fault on my line & it took them 3 hours to fix it. Mind you, the Openreach guys were very helpful & at the same time did my fibre pre install even before I'd ordered it through PN.

[#8]

They've said they'll look into it within 7 days. I'd be over the moon if they installed fibre, but there's zero chance of that!

[#9]

I was amazed to see an Openreach van & technician by my green cabinet this morning, New Year's Day. He said he was helping to catch up with the back log of faults caused by the atrocious weather & that he was being well reimbursed for his efforts. I was most impressed!

[#10]

And we're through the floor, my router won't sync at all now.
I'm supposedly working from home this week. 

[#11]

Is the phone still working at all?

[#12]

Yes, the line's really quite noisy now though.