I did some measurements a while back and the "old" PSU is running at under the design capability when on 17c ... and it works fine with the older and newer modems.

There are two possibilities for needing the extra 3.6W (or so):

Firstly, some devices may be at edge of tolerance and consume additional power even on 17c or;

secondly if/when BT go to the 30MHz scheme then it will need additional power.

When I get the chance, I will measure again.

Had mine changed by an Openreach engineer today. No PSU in the box, but when I asked for a replacement he got a spare from the van. Until I mentioned it, he hadn't noticed that the new modem power rating is more than the old PSU can supply. He will inform his mates.

I will, of course, update this thread after the visit. Got an evening slot.

DrT

Chap just visited. The modems do NOT come with a PSU in the same box any more, they used to. The chap seemed to know that the PSU should be replaced and said was picking up a box of 10 from the stores and should be bringing one before Friday.

DrT

Edited by deleted (Mon 27-Feb-12 18:29:27)

In reply to a post by DrTeeth:

The modems do NOT come with a PSU in the same box any more

They did last week!

In reply to a post by kasg:

They did last week!

Spit .

DrT

Our modem was replaced last week and the Kelly engineer said no PSU and cables in the new boxes.
Could be that some boxes have no PSU's for replacements or someone could be taking these out of the boxes prior to comming into the house?
Think someone at BT management needs to say what should have been replaced or not replaced.

Hi All

We�ve checked this for you and can confirm that the PSU does not need to be replaced, both models of PSU are suitable to power the new modem. Initially during the early part of the replacement programme some customers may have received a replacement PSU, but this is not necessary so the PSU is no longer being replaced.

Hope that helps clarify things for you all.

Regards David

In reply to a post by BT_Care:

We�ve checked this for you and can confirm that the PSU does not need to be replaced, both models of PSU are suitable to power the new modem. Initially during the early part of the replacement programme some customers may have received a replacement PSU, but this is not necessary so the PSU is no longer being replaced.

Regards David

I don't think that is right David.

The PSU on the old modem is rated at 0.6A output. The old modem has a peak requirement of 0.7A.

The new PSU is rated at 1A, which is the peak requirement of the new router. I assume PSUs have output ratings for a reason.

I also checked independent of BT Care and same answer