My lap top not log on first : the usb failed then : the monitor not show any thing

Hello
Is it show your profile page on your own laptop ?
do your laptop open other webpage ?

Try this: log off then turn off lap top, insert the USB devise into the USB port, power / turn on and log in it should show to recognize new hardware and work.

Darkened screen as you describe indicates a failing inverter. You can test this easily by plugging the laptop into an external monitor, if this works ok, then the inverter needs replaced, If it does not work, the problem is with the graphics chip / motherboard

There is problem in cablee

Did you use the combination keys of your laptop Fn and either F5, 6, or 7 depends on brand to select internal/external/both? You also need to make sure that the video resolution feeding the monitor is at native resolution setting.

http://www.fixya.com/support/r6150077-basic_lcd_monitors_troubleshooting

Failed TV and Monitors: http://s807.photobucket.com/home/budm/allalbums
http://en.wikipedia.org/wiki/Capacitor_plague

• Attach two monitor and switch on the laptop
• automatically second monitor will show diplay
• if not then find out dual display symbol on the taskbar click on it.
• window will open select dual monitor
• click apply
• if not then right click on desktop --properties--desktop two monitors symbol will see select 2nd monitor

Cause If you connected the monitor power already is on, you may not get signal. Power plug off the monitor first, Then connected to laptop. Then power the laptop and power the monitor. FN key press hold with your Monitor swicthing key which symbol of two monitor shows on key probably number 5 or 6 maybe 7 check user guide if you have it.
another cause is your monitor may need driver install in your laptop, Some system required that. Check monitor system requirements.
JMC

If you don't have the wireless password for your wireless connection. The thing to do is log into the Router's webpage via the Router's IP address. From there you can go to the wireless section and in most routers this section shows the wireless password.

If you have trouble getting on to the Router's webpage. Just comment back on this and I can probably step you through it.

Both of you, what did you do before the restart? If you changed anything while in Winblows it seems likely it is a software related issue. If you didn't, then a hardware issue is possible, in which case I'd start by unplugging the non-essential peripherals and restart. If that doesn't work, also try a different power supply and disconnect the battery. Sometimes a bad peripheral can cause the boot up sequence to hang. And correct me if I'm wrong, but I believe a weak psu can undersupply power to the harddrive causing the operating system to fail to boot. But, you probably have tried these ideas so they may not be of much help. Oh well, good luck!

When you first switch on Does it show Benq?If not the inverter circuit has failed.If you are technically able you can try resoldering transistors on inverter board.If your display is black all of the time transistors could have failed as also related fuse etc.
And yes please check with BenQ Normally these have a 3 year warranty.