Some of you may have seen the thread "What the hell's happened to my line?"
a few days ago - in which I eventually concluded that the problem was down
to a poor power supply connection on my router.

Well, the problem has returned - and it isn't what I thought - but it's
definitely to do with the router [3Com 3CRWE754G72-A]. The symptoms are as
follows:

When the router is switched off for a while and allowed to cool fully, and
turned on again, it works perfectly for 2 or 3 hours - and then the
performance starts to degrade. When it's OK, PlusNet's line speed test
returns a consistent 460+ kbps figure (on a 512k line) and the router
reports a downstream noise margin of about 24dB - and there are very few CRC
errors. When it starts to misbehave, the noise margin goes down to 15dB or
less, there are thousands of CRC errors and browsing becomes almost
impossible. If I can get the speed test to run at all, it reports speeds
down to 30 kbps! Eventually, the router loses synch and I can't connect at
all.

I *know* it's the router and not the line because:
(a) if I allow it to cool, it's ok again
(b) I have an alternative method of connecting using a PCI ADSL modem in old
PII computer - and that works perfectly with no time limits

When the problem occurs, both the router and its plug-in power supply feel
fairly hot - not too hot to touch, but probably 60 degC at a guess.

Has anyone else experienced this type of problem with this router? Does it
have a known temperature sensitivity?

I know that the obvious answer is to chuck it back at 3Com - but unless they
test it for long enough (and possibly if they test it in an air-conditioned
lab) they may not find the problem and would probably then try to charge me
for their efforts. Does anyone have any experience of 3Com's after-sales
support in this kind of situation?

One more question. The router still has the firmware with which it was
supplied - which has served me fine for the last 14 months until recently.
There have been several firmware updates released since them, at least some
of which mean that the thing has to be re-configured from scratch since
they're apparently not compatible with earlier backups - so I've resisted
updating the firmware. Can anyone think of *any* reason why updating the
firmware might fix my problem - because it seems unlikely to me? Does anyone
know whether firmware releases are cumulative - so that if you install the
latest one, it automatically includes all the earlier fixes?

TIA.
--
Cheers,
Tim
______
Please reply to newsgroup. Reply address is invalid.

On 15 Jul 2005 14:40, "Tiscali Tim" <tele@privacy.net> wrote:

Not the same router, but a couple of the cheap ones I have here (< 25 quid)
from Ebuyer (the AR11 and the Safecom single port models) were also acting up
4 days ago (the user interface wasn't working, there was no transfer of data,
but looking at the error log today for the Safecom, it just shows me fairly
ordinary activity (connected, disconnected soon after - probably when I was
doing some testing and swapping from one to another) and I reconnected the
Safecom a few moments ago, to see how well it copes...

The single port units are in very small boxes with poor/limited ventilation,
while the 4-port units (I had the AR41 handy) has a larger box and worked
without any problems in the meantime. I suspect 3Com will just say "it's
been extra warm in the UK, provide better ventilation in the room" if you
bother them with a fault report, unless is continues even after a cooler
spell of weather. At a wedding in Portugal recently it was 42C, so I've
no idea whether the equipment sold over there is capable of withstanding
higher ambient temperatures, or whether people use a/c wherever their PC
equipment goes to ensure it won't just lock up. Peter M.


--

UK ADSL <http://tinyurl.com/5jpa4> - Happy to save cash with Plus.Net!!

I have one of these at home and three at various office locations
linked to the business where I work. Mine at home has been troublesome
from the start and it has been replaced once by 3Com after flashing it
to the latest firmware dropped my 1MB Plusnet connection of 200kbps!
It then locked up completely!

They are very troublesome in hot weather and we have recently been
installing them outside of the data cabinets to prevent overheating.
In one instance, this has almost stopped the disconnects completely.

I have moved mine at home away from the window so that it is away from
the glare of the sun. We have 15 remote sites and have standardised on
the much more expensive Draytek equipment which doesn't seem to have
any of the problems of the 3CRWE754G72.

Cheers
Mark

Tiscali Tim <tele@privacy.net> wrote:
Yep. I reckon it's a product fault. A friend of mine had no end of
problems with his, and with the factory replacement. Support recommended
upgrading the firmware, which he did but to no avail. In the end we
replaced it with a completely different make/model and all the problem
symptoms vanished :-(

Chris

On Fri, 15 Jul 2005 14:40:52 +0100, "Tiscali Tim" <tele@privacy.net>
wrote:

When under load the signal strength is up and down like a yoyo until
the connection to the PC drops (after about 1 minute)

However I think its the adapter I use which gets very very hot.

It is a 3Com USB key

My other PC has a cheap-o Ebuyer USB adapter and it has been very good
with no drop outs.

Once the house was cooler the signal was strong and didnt drop once on
the PC with the 3Com adapter.

As a side note its also crap at reparing the connection after a fail
like this. The only way I can do the repair is to remove it from the
hardware configuration and add it back in again.


Harry


-----------------------------
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"Tiscali Tim" <tele@privacy.net> wrote in message
news:3jpsmtFrbbcpU1@individual.net...
had trouble, but wanted to keep it reliable.
I pulled off the self adhesive plastic label strip that is on the front
panel. This reveals some holes in the case. I then mounted the router
vertically, i.e. sockets at the top LEDs at the bottom, and the natural
convection keeps the router nice and cool, even during the hot weather we've
been having. OK so you loose the labels for the LEDs, but who cares if it
makes things more reliable?

My power / socket unit only runs slightly warm to the touch - if yours runs
hot then I would definitely return it to 3Com UK as this could be a fire /
safety issue.

The firmware updates do nothing for the temperature issues, but you should
install them (or the latest one, since afaik they are cumulative) so as to
obtain the best security and performance available. You will have to
restore / reconfigure all your settings - but that's no big deal is it?

Avril

"Tiscali Tim" <tele@privacy.net> wrote in message
news:3jpsmtFrbbcpU1@individual.net...
Get the latest firmware on it. 1 fixed a big security hole. This unit does
run hot but ought to be able to cope unless faulty. I had Netgear and
Linksys wireless routers which were both useless before going for the rock
solid 3Com. Apart from a Draytek I don't think I'd trust anything else.