In reply to a post by zom22:

It probably needs the PN IP setting to be given a nudge - it will be stuck at the low level.

Sorry, just realised that we are on wrong track here.

Stuck IPP shows itself as low throughput, not low sync. IPP is a function of sync not t´other way round.

Ah sheeeeeeeeeeeeeeeeet
I misread the OP's first post as download still 6.6 rather than the sync speed still 6.6
My fault - I'm sorry

So despite the fault being 'mended' the router's sync speed which was 15Mbps prior to the fault is now only 6.6Mbps?
Goodness knows what it was during the fault - even worse no doubt.
That would suggest that there is still some fault present on the line.
(I'm better not make any more suggestions.......before I make a bigger mess)

Glad we got there in the end

Target noise margins are probably high and if line now stable should come over a few weeks or if in a rush might be persuaded to prod a reset

Does your parents' router display the SNR margin? Depending upon line length, this ought to be between 6dB and 12dB (probably nearer to 6dB given a previous sync rate of 15Mbps).

It sounds to me that the line may be banded by BTW, although obviously, without checking your line, I cannot be sure. If this is the case, an SNR reset should do the trick.

Suggest raising a fault at http://faults.plus.net

Just checked again now by remote logging in:-

15600 kbps Down/ 1167 kbps Up

In other words back to normal. No rebooting since the line was fixed, just seems
to have restored itself, all by itself.

Thanks to all that responded