USB devices don't connect at bootup

  JE-KM 11:17 06 Aug 2004


I have a problem with a new Tiny laptop I have...

When I plug in my USB ADSL BT VOYAGER modem, it gets detected and works fine. (no problem so far).

But if I boot up the laptop with the modem already plugged in, it is not identified until I unplug it and replug it back in.

I have not tried other USB devices on this laptop yet. It is a USB2.0 architecture.

I also have the same problem on my desktop with my Kyocera laserjet - but the modem is fine on that.

Any solutions?

  JE-KM 14:04 06 Aug 2004


please help!

  Fruit Bat /\0/\ 14:48 06 Aug 2004

click here for USB advice

  €dstowe 14:56 06 Aug 2004

At startup, computers need as much power as they can get to get all the drives spinning, CPU in operation and so on - much like an aircraft at takeoff. When in the air, so to speak, the power requirement are much less and everything relaxes.

Modems - especially USB modems - take power from the computer. This may well be power that it can'tafford to give up during the strain of starting up (takeoff) and therefore get left behind for more urgent matters. Of course, when everything is going there is power to spare and the modem gets its power without any problem.

I wouldn't normally suggest this but, it may work out OK, if you connected your modem via a powered hub (note: powered hub is important, a passive one wouldn't do what I intend). This takes the need for power away from the laptop and lets it get on with powering up.

I normally think that modems should be connected directly to the motherboard but this may provide a workaround. Other than that, disable all other non-essential hardware in the startup process (unlikely to be much,if any, though).

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