Mystery problem - USB port and RADSL

[Mark Frank]

I have a client who has recently installed RADSL (Pipex as it happens - whose customer service is appalling - but that's irrelevant). It started at 5 Mbs and worked OK. Then it went up to 7 Mbs and stopped working. The funny thing is the problem went away when we moved the modem to a different USB port on the same machine. It is absolutely repeatable. Move the modem to one port (where it worked OK at 5 Mbs) and it can't sync - move it to either of the other two ports and it works fine. What on earth could be going on? I can't see an explanation and I don't like not knowing.

[peterb]

If the PC is a laptop it could (only could) be that it is on the edge of its power capacity, and at higher speeds the modem is drawing more power which is just that bit too much. Otherwise it could be that the PC is running out of processing power at higher speeds, or a driver problem or... any number of things. USB modems are fine for simple undemanding setups, but you are really better off with an ethernet modem/router tbh.

Is anything else plugged into a USB port on the computer? It could be that the USB bus can't hack it... (unlikely)

[Sinizter]

Some of the USB ports might not be powered.

Modems install a copy of the drivers for each instance of it being plugged into an USB port. So if you moved it from the initial port to the 2nd it installs a 2nd copy of the drivers. So the first copy of the drivers may have been corrupted. But that doesnt really seem to logical as then the 2nd set would be corrupted too.

The higer power draw from the first port may have damaged the usb port in some way, so the error is recreatable.

If the first port works with other devices without issue and the second port works with the modem just accept that it is so and use it like that?

[streetster]

usb 1.0 versus usb 2 perhaps? not enough bandwidth over 1.0 (1.5mbps compared to 480mbps) ?

[chuckskull]

USB and internet never mix well, always throws up all kind of fun errors, connections drops and so on. 9 times out of 10 switching to ethernet will fix all the probs.

[Mark Frank]

Thanks for all the hints. Nothing else using USB. It is USB 2.0. We reinstalled the driver when trying to fix it. I guess I will just never know the answer.

[badass]

Thanks for all the hints. Nothing else using USB. It is USB 2.0. We reinstalled the driver when trying to fix it. I guess I will just never know the answer.

If in doubt, smash it with a hammer!