I have exactly the same issue with a brand new 2830N on plusnet. I've emailed draytek but it sounds like the whole range Is broken when it comes to built in ADSL modems

Ok guys, so 48 hours on my router has been solid on VDSL with no appreciable drop in speed, sync is maxed to 80/20 and speedtest.net showing similar results to when I was going though WAN2 to the BT supplied modem.

Bear in mind I had mine RMA'd where they'd apparently fixed the ADSL part of the modem which I found to work fine so long as the correct profile was on the line from the ISP end. This might have meant the VDSL part could have failed also without the RMA but I'll never know.

Either way things are looking up for this 2850n, at present on firmware 3.6.2_232201 (May 4 2012 11:27:45) so I'm hoping that might rule out fundamental issues with the hardware and firmware, once fixed on the RMA and with an appropriate profile (SP20) on the line for ADSL2+ and out of the box on VDSL. Given my ADSL2+ was on a very long line from the exchange with around 3M down / 1M up rates and my VDSL is very short line with full 80/20 sync pulling in real life around 75/15M.

If you have the time and patience (and potentially a helpful ISP like I had) I have hopes that people will be able to get results from their devices too.... or maybe I've been lucky.

Will report back if there is any change on my line condition as 48 hours might be a little too soon to break out the champagne.

My 2850vn worked fine with Be for the first 6 weeks then started playing up with persistent disconnections and reconnection failure. I know that Be are upgrading their core network so thought i would check with them to see if anything in my area had changed. Went through some basic troubleshooting steps which i didnt think were necessarily relevant but humored the technician who has to follow procedures. In order to reduce the ADSL cable length i had to physically relocate the router closer to the phone socket. As I did so I noticed that the plug felt hotter than I thought it should be.
Lo and behold, on plugging the router back in - no power. Nothing.

Now, I can accept that hardware failures can happen but here's what I don't understand. Why am I being charged £16.80 to purchase another PSU for a product less than 2 months old. I then have seven days after receiving the replacment PSU to return the faulty one. If it has not been received by that time I am not entitled to a refund. Apparently I should receive a "refund" if, after testing, it is confirmed that the PSU has failed.

To summarise the hilarity of this situation and potential outcome:
I send an email to Draytek Support describing the situation. They advise me to order, i.e. "purchase" a replacement PSU. I pay for a new PSU. I pay for the postage to return the faulty PSU. If the router does not reach them within 7 days of me receiving the replacement PSU (picture the postman on his mobile phone at my doorstop: "OK Draytek, he's got it. Start the clock!") then I don't get refunded. If it turns out that the fault is with the router and not the PSU, then I don't get refunded.

Happy days! Anyone see a problem with this methodology? Remember, this is a faulty and unusable router which is less than 2 months old.
Frankly, I do not agree with this and I've told support by email that this is not acceptable. They either send me replacement parts at no cost to me or I get a refund. If I'm not satisfied, then I don't buy their products. I slate their products at every opportunity to my friends and colleagues (I work in IT). This is my right.

The fault lies with the product which DRAYTEK manufactured, assembled or otherwise put their name to. I did not break it. I am not at fault. I will not spend a further penny on addressing Draytek's shortcomings.
Draytek, if you don't care about your products and care even less about your customers, you will lose business.

Apologies to anyone who feels this has been posted in the wrong forum. I couldn't find the Rant Forum.

I agree with you Ground Hog, when something is faulty you don't expect to pay to rectify it when it is within warranty. I'm not sure on the legal implications of who is expected to burden costs with regards to postage etc but I always thought most places have a freepost or similar set-up for returns but will charge if the goods are found to be not faulty.

I would have taken them to task on this for my return but frankly had expended enough time and energy on the problem to warrant getting into any kind of argument over refunding of costs. Good luck with your pursuit!

@MrJolly.
Thank you for your kind words.
I appreciate that sometimes its quicker, easier and less taxing to just pay a small amount to get something done. Don't blame you at all. Apologies for my rant but I find it helps... :oops:

Update: just received a positive email response from Draytek Service Centre:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
"The warranty on your product is a return to base warranty, which means
if any thing goes wrong with your router, or the accessories, you must
return the product to our service centre for test and reply.

As  a  good will gesture, we will ship out a replacement power supply
to  you, and we will ask that once you have tested the replacement PSU
and  all  is  working  okay,  that you dispose of the faulty PSU in an
environmentally friendly manor.

Please  provide you address for us to dispatch a replacement PSU, also
please confirm which product you have, and the product serial number."
~~~~~~~~~~~~~~~~~~~

So, there is hope after all.
I'm fervently hoping that there are no other issues once I've received the new PSU.

Nice one, and good on them. Sense usually prevails.