Unknown device for PL2303 USB-to-Serial

nihaojs · 19th December 2004

Dear All,

I bought cable which can connect my PC (window xp sp2) USB to Mobil phone Siemens CF62.
According to the instruction, I install thr driver for the cable. It shows PL2303 USB-to-Serial. In user manual, it explains that after install driver, it should creat a COM3 in device manager, but I didn't find this item in the device manager.

I connect cable to USB and then connect to my mobile phone. Wind satrts automatically install drivers. But finally it shows in device manager--usb controller as UNKNOWN DEVICE. I checked the driver which shows 'standard-USB-Hostcontroller from Microsoft'. It seems to not the one I installed.

How and where can I find out the driver I installed?
Is this cable defected?

Thanks!

NH

**mattman** · 20th December 2004

Hi nihaojs,

"Standard USB-Hostcontroller" sounds like you do not have the correct drivers installed. Try looking up your motherboard model at the motherboard manufacturers website and see if there are USB drivers there. You may be redirected to the chipset manufacturer's website. (The USB on my Gigabyte board would not work correctly till I got the VIA USB Controller drivers.) They should be on the driver disk you got with the computer, but the manufacturer's website will have the latest version.

You do have the motheboard/chipset drivers installed? Look under IDE Controllers in Device Manager. The drivers should be listed as VIA, Intel, SIS, etc IDE controllers, not Standard Microsoft ones. If not, install the chipset drivers before you install any others.

If you like, post back with your motherboard model and I may be able to help you find the ones you need.

Matt

nihaojs · 21st December 2004

Hello Matt,

Thank you for your reply. The USB works fine on my PC. I mean I can connect some device on my USB port without any problem. I checked with IDE Controllers in Device Manager as you suggested.
It shows:
IDE ATA/ATAPI Controllers
Intel(R)82801EB Ultra ATA storage Controller
Primary IDE Channel
Secondary IDE Channel

I hope I checked right position. By the way my motherboard model is Fujitsu Siemens Scenic D1561.

Thank you in advance for futher instruction.

NJ

PS. I am not sure whether this data cable is defect.

**mattman** · 22nd December 2004

nihaojs,

I should read the question in more detail

(put my glasses on

). We are concentrating on getting the cable installed on the Serial connector (Com Port). It seems like the motherboard/chipset drivers are OK.

If you highlight and go to "Properties" for the PL2303, it should tell you which Com port it is installed on.

Does the PL2303 driver seem like the correct one? Try this: go to Device Manager and "remove" the driver. Check if there are any listings in Add/Remove programs for the cable and remove them. Shutdown and disconnect the cable. Reboot into Windows and run the driver installation again. Reboot again before connecting the cable, see if it installs a new Com port. If it does not install a new Com port, connect the cable and reboot again. I think it will need to install the new Com port before you try to connect the phone (in other words, if you connect the phone without getting it on the "new" Com port, Windows will set the drivers that way and you will be back to where you are now).

Make sure the cable is connected/seated fully.

After you get the new Com port installed, you should remove the "Unknown Device" in Device Manager. Hopefully, when the cable/Com port is running, Windows should recognise and install the drivers for the phone, when you connect it.

mmm...Another trick may be to remove all the Com ports listed in Device Manager and make Windows reinstall them on reboot. It may then install the "new" Com port.

It should not cause problems to remove old drivers and let Windows reinstall them. You need to get Windows to install them correctly.

Matt

itayb · 30th December 2004

Hi,

well, i just got myself a new USB 2 IDE cable (where i can connect any ID device to the computer using a nice USB cable).
the computer recognizes it as an "Unknown Device" - and i just cannot change it. whatever driver i try to install it doesn't work. it continues to identify the device as "unknown device", and even when i try to configure it as something else (a cd-rom for example) it doesnt let me.
i tried this cable on another computer and it worked just fine - without any drivers.

I am using Win XP SP2.

what can i do to remove this "unknown device" option (maybe out of my life once and for all) ?

Thanks

**Rockster2U** · 30th December 2004

nihaojs:

Just did a quick search - is that PL2303 driver perhaps a linux driver for the Prolific USB to serial adapter? Are you sure? Do you have the correct version?

Personally, I'd remove the unknown device in device manager, disconnect your adapter and then follow this link.

**mattman** · 30th December 2004

itayb, suggest you go to the motherboard manufacturers website and find the latest motherboard/chipset drivers and install those. They may well include updates for SP2. If the "unknown device" comes back, try uninstalling the USB Controller drivers and make Windows reinstall them on reboot.

Still no luck...that cable may need to be set up under the IDE Controllers, so try unistalling and reinstalling those.

Matt