Service manual

Belinea 101910
4. THEORY OF OPERATION
This section describes the function of the LCD monitor per functional block.
The Belinea 101910 monitor includes MB board (including audio board function inside), power board
and button board.
4.1 MB BOARD
The MB board is a two-layer, single-landed design with ground and ground planes provided.
The VGA cable is a signal cable that contains video signal, sync signal and DDC signal from PC VGA adapter.
This system board consists of 3 functional areas: flat panel controller, Micro controller and audio controller.
4.1.1 Flat panel controller…… Mstar MST8131A (U3)
The heart of the system board is Mstar MST8131A. The MST8131A is a graphics processing IC for
LCD monitors. It provides some control functions required for LCD panel. On-chip functions include a
high-speed triple-ADC, PLL, high scaling engine and OSD controller.
a) Clock Generation :
Crystal Input Clock (XTALI and XTAL). This is the input pair to an internal crystal oscillator and
corresponding logic. A 14.318 MHz crystal is recommended.
b) Hardware Reset ( Pin 32 )
Hardware Reset signal is generated by MTV312 (U5/Pin 26). It asserts a reset signal at least 1 ms.
c) Analog to Digital Converter
The MST8131A chip has three ADC's (analog-to-digital converters), one for each color (red, green
and blue). The analog RGB signals are connected to MST8131A as described below
Pin Name
57Blue -
58Blue +
59Green -
60Green +
62Red -
63Red +
Pin Numbe
r
MAXDATA Servicemanual 111908 Page 20
- Confidential -