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Usb 634 Lcd Backlight

Rick Tucker

New member
I was wondering if there is a way to enable the backlight all the time. If I power on my computer I want the bootscreen displayed and backlight on.

My computer has long boot times due to scsi devices being enabled.

I setup the display using the boot screen utility and it does not turn on until just before entering windows.

I know that there is power to the Usb cable as soon as you power up the computer. Why doesn't the boot screen show up then??? It does not turn on until windows loads drivers just before entering windows????

Thanks
Rick Tucker
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CF Tech

Administrator
USB manages the power usage on the bus.

If you plugged 8 USB devices into two passive hubs, and each device drew the maximum of 500mA each, then the 4 amps total would certainly be more than most USB hosts can provide.

The way USB gets around this is that the USB devices are required to wake up in a low power mode. Then, as the bus is enumerated, the USB host asks each device how much current it needs. If the total is too much, some devices would not be initialized and would stay in low power mode.

So what it comes down to is that a well behaved USB device will not draw power until it is initialized by the OS.
 

kronchev

New member
Try enabling USB mouse and keyboard in the BIOS. I think that will give it all the power it needs upon bootup. Itll go off-on quickly when windows starts up as windows retakes control from the BIOS to its own protocol but it SHOULD be lit the whole time.
 
USB LCD Displays - Graphic and Character LCDs with a Keypad
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