Dell ST2010 - 20" LCD Monitor, Руководство по обслуживанию

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Service Manual
13
energy when current is reversed. The parts including C862, C8
63
C864 andL852
are used to smooth the current waves that are from D855, then 13V voltage is
supplied.
D856 is a SCHTKY diode used to rectify the inducted current.C866 and R866
are used to store energy when current is reversed,The components including
C867,C868andL851, C867 and C868 are used to smooth the current waves,then
DC+5V voltage is supplied. F851 is used for OCP for the LPS test.
DC 5V supply voltage feed back to PWM controller U850 via,
R861,R860,R859,C859,I851,R867
Used to control the voltage feedback loop.
2.3 I/F Board Circuit (see the Attachment 2- Schematic)
2.3.1 RGB CAPTURE
- Signal RED,GREEN,BLUE input through CN102 #1,#2,#3, Stop DC via C113,
C114 and C115, and then enter into U105 (TSUM58EDJ-LF) analog input
PIN #28,#25,#23, and then TSUM58EDJ-LF deals with signal internally.
D103, D104, D105 are ESD protector to prevent U105 from ESD.
- Signal DDC_SCL (series clock) inputs via CN102#15, and then passes through
ZD106 for ESD protection, goes into EDID EEPROM IC U103 #6.
- Signal DDC_SDA (series data) inputs via CN102#12, and then passes through
ZD103 for ESD protection, goes into EDID EEPROM IC U103 #5.
- Signal TTL vertical sync. (Vsync) inputs via CN102 #14, and then clamped by
ZD105 Zener, passes through R116, and then goes into IC U105
(TSUM58EDJ-LF) #33.
- Signal TTL horizontal sync. (Hsync) inputs via CN101 #13, and then clamped
by ZD104 Zener, passes through R115, and then goes into IC U105
(TSUM58EDJ-LF) #32.
- CN102#5 is defined as cable detect pin ,the detect pin can create a pull-low
signal send to U105#36pin via R160 to identity cable connection, if plug out
the VGA cable the U105#36pin will receive a high signal and system enter self
test mode when exit factory mode
（
the device must set at VGA input mode
）
.
- U103 is an EEPROM IC which is memory and EDID data saved in it,the IC
power is supplied by PC via CN102#9 with D106 and ZD102 for ESD protection,
or supplied by Monitor self via D106.
2.3.2 HDMI CAPTURE
- TMDS differential Signal input
RX0+,RX0-,RX1+,RX1-,RX2+,RX2-,RXC+,RXC- through CN201
#7,#9,#4,#6,#1,#3,#10,#12 via R206,R205,R204,R203,R202,R201,R208,R207
enter into U105 (TSUM58EDJ-LF) Digital input terminal
#15,#16,#12,#13,#9,#10,#18,#19, and then TSUM58EDJ-LF-LF deals with
signal internally.
- Signal DDC_SCL (series clock) inputs via CN201#15, via R209, goes into
EDID EEPROM IC U201 #6.
- Signal DDC_SDA (series data) inputs via CN201#16, via R210, goes into
EDID EEPROM IC U201 #5.
- CN201#17 is defined as cable detect pin, the detect pin can create a pull-low
signal send to U105#3pin via R158 to identity cable connection, if plug out the