Recently the usb connection from my N800 to my PC stopped working.
There no usb icon on the n800 and nothing on the pc.
I tried to re-flash the N800 using a Windows XP box. The usb Icon showed up on the top right of the N800's screen but the windows box did not see the N800.
Oddly, when I plug in my OTG adapter to the N800 it works fine, reading any powered device that it is plugged into.
Any Ideas?

Maybe the N800 is stuck in host mode?

On your PC, did you install an additional drive? installed a software that creates virtual drives? created a new mapped drive? if so, then (connect your N8x0 to the PC) right click My computer/manage/storage/disk management, on the right hand panel, scroll until you find your drives from the N8x0, double click on each one and assign a different letter from what it used to get. Open My Computer and it should appear, if it doesn't reboot. If it still doesn't make sure to try different USB ports.

I tried a few things to reset the usb mode, including a trick where you pull the battery for 30 minutes, reinstall the battery plug in the charger and press the swap/home button. it powered up with most of the settings reset to default but no change in the usb problem.
I tried using the usbcontrol utility to no avail.
I tried it on a Windows XP machine using Superstar's instuctions. I had not made any HD changes.
I tried a several different cables and usb ports.
I tried several different SD cards.
I get the same reaction from the computers and the N800, Nothing.
And yet when I try to flash the unit,on the XP machine the usb logo shows up in the top right but the software does not see it.
And still, when I use the OTG adapter it reads my Fuji camera just fine.
I'm perplexed.

Oh Yeah,
I tried this too.

xterm
sudo gainroot
echo host > /sys/devices/platform/musb_hdrc/mode
echo otg > /sys/devices/platform/musb_hdrc/mode

Try downloading the Nokia PC Suite Software (from Nokia website) its normally used just for their phones, but as I also have a N95 phone I have the SW on my PC. I have had lots of problems with USB and PC connection, but found 2 things that worked 1) SWAP USB cable - for some reason some USB cables do not work with my N800, no idea why, but i have 2 of the 5 USB cables on my desk that simply refuse to work with my N800 2) Nokia PC Suite - it allows you to browse your memory cards via the Phone Browser, so you can load files on/off your N800.

I'm going to bet that your stuck with problem 1, assuming when you switched PC's you used the same USB cable.

BT

I'll keep trying things. But I think you may be right. When this problem first showed up I thought it'd be about a 50/50 chance that it was a hardware problem.
I ran the latest upgrade last night, Hoping that that would fix it, but no.
The workaround is obvious and easy.
If I find the solution, I'll post ti here.
The fix may involve a new N810 for Christmas.
Thanks to all for trying.
Alan

I have the same problem. USB ( and wireless ) stopped working, I'm not sure if this is true, but it seems. That it happened after a online update.
And I can't reflash it since my PC ( windows and linux ) won't detect it.

There's a couple of ways to reset your N800 in the instruction PDF at the Nokia site. Being that you have no Internet, I would try these. There's a "soft" reset (PDA terms) and a "hard" reset. I don't know how hard the hard reset is, but if my device couldn't connect to the net, I'd definitely try that.
Also, I wonder if theres a way to put a image on an SD card and re-flash the N800 from that? Hmmm.
Alan

Here it is.

"You can also use the control panel to sort of "reset" the device. Click Control Panel then click the menu of it on the top left and goto Tools > Restore original settings or clear device. both of those options will leave some files intact...not a pure reset like re-flashing it however."
from
http://www.internettablettalk.com/fo...ad.php?t=12835
Try it. Tell me how it goes.
Alan