Prestigio VISCONTE 120 Technical & Service Manual page 22

Prestigio Visconte120
Because fan will consume some power and make some noise, the system will try to keep the fan in low speed and keep the
system in high performance as possible. Unfortunately, there are some trade-off among some factors: thermal, noise and CPU
performance, so we increase the fan speed as active cooling method and triger the CPU clock throttling as passive cooling
method. The CPU clock and fan speed is controlled depend on the CPU temperature from hardwire thermal monitor.
2.6.6 The backlight control of LCD
The LCD panel is another key parts that will consume more power of the notebook system, so there is a way to reduce the
power consumption on battery only, e.i. reduce the brightness of backlight when end-user unplug the AC adaptor.
The backlight is controled through the KBC controller, and it is divide into 8 levels from darkest to brightest. The KBC
bios know the status of power source and the current backlight's brightness any time. When the AC adaptor unplug, the KBC
will reduce the brightness one or two level automatically.
There is another approach to control the backlight, it will be turn off when LCD cover is close (LID switch), conversely,
it will be turn on when LCD cover is open
2.7.1 Crisis Disk
Crisis Disk function can recover the BIOS back if flash BIOS fail and can't boot up due to lost power while BIOS flashing or
any other situations. Operation as below:
2.7.1.1 Crisis Disk options: There're 3 kinds of Crisis Disk options (Press Key Conbine) as below
2.7.1.2Ctrl-Home: NVRAM data (DMI string) will be preserved, CMOS data will be destroyed after
flash.
2.7.1.3 Ctrl-PageDown: both NVRAM and CMOS data will be preserved.
2.7.1.4 Ctrl-PageUp: both NVRAM and CMOS data will be destroyed.
2.7.1.5 The correct way to press these combine key is, Press and Hold "Ctrl" key, then Press and
release the second key (ex. Home) several times.
2.7.2 Prepare a Floppy Disk contain BIOS ROM file
2.7.2.1 Complete Format a Floppy Disk, to make sure there's no bad sector
2.7.2.2 Rename the BIOS ROM filename to "AMIBOOT.ROM" and copy this file into the Floppy Disk
2.7.2.3 Insert the Floppy Disk into USB Floppy Disk Drive
2.7.2.4 Insert the USB Floppy Disk Drive into any USB port
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TECHNICAL SERVICE MANUAL