5-5-2. Troubleshooting Table of Video Controller Board
NO.
Error Type
Ckeck List
Repair
Power cord connection
Connect the power cord
Vcc voltage(nominal is +5V) level
Refer to the section of
Vcc voltage should be in the range 4.38-+5.2V
Engine troubleshooting
The backlight
Short Between Vcc and GND
Repair board
1
of LCD is not
Mutual connection of engine, key panel to LCD
lit up
panel’s connected cable(10pin), video board to key
Connect the cable to
panel’s connected cable(20pin) and engine interface
connector
cable(28pin)
The pin of connector is straigh.
Mutual connection of panel cabel(10pin)
Confirm the connection
video board to key panel’s connected cable(20pin)
of connector
Repair or replace it
Any component damage on a video controller board.
with appropriate tools.
It doesn’t
If uanable to do this,
2
displayed
replace video board.
characters on
Any foreign conductive chips of solder or material
Remove any foreign
LCD
is on the video controller board or is laid between
conductive chips on the
IC pins after power off.
video controller board.
Reset Error:Reset signal is normal high during operation
System source clock is a 50
MH
Z
Check point : U21(FS741)’s pin No.6,
Replace the FS741
The output clock of SPGP1 is a 25
MH
Z
The input clock of CPU(U18) is a 25
MH
Z
Replace the board
The video data colck source is a 62.7639
MH
Z
at OSc1
The input clock of U23 is a 62.76397
MH
Z
3
White copy
The output clock of U23 is a 16
MH
Z
The input clock of U18’s pin No.125 is a 16
MH
Z
Replace the board
*
Check the normal operation of HSYNC* and PSYNC*
Active low impulse
4
DRAM Error
*
Check the DRAM address signals.(pin No. 17-20, 23-28 : U19, U11)
*
Check the DRAM data signals. (pin No. 2-5. 7-10. 33-36. 38-41 : U19, U22)
5
EEPROM
*
Check the EEPROM clock signal. (pin No. 2 : U1)
*
Check the EEPROM data signals. (pin No. 3,4 : U1)
6
ROM Error
*
Check the ROM chip select signals and read signal (pin No. 12,14)
*
CHeck the ROM data signals. (pin No. 15-22, 24-31 : U3, U14, U2, U13)
7
Engine Error
*
Refer to the section of Engine troubleshooting
Parallel
*
CHeck the operation of printer driver.
Refer to USER’s manual
8
Interface
*
Check the printer cable(bidirectional cable)
Replace the printer
Error
cable
General desc-
*
Please refer to the user’s manual.
9
riptions of
*
If you can’t fix the trouble of video controller
Replace the board
troubleshooting
board, replace the video board by the verified
board.
Troubleshooting
Samsung Electronics
5-17
Summary of Contents for ML 7000
Page 53: ...MEMO Samsung Electronics 5 18 Troubleshooting ...
Page 55: ...Samsung Electronics 6 2 Exploded Views MEMO ...
Page 57: ...Samsung Electronics 6 4 Exploded Views 850 856 855 853 857 851 852 854 858 850 2 850 1 ...
Page 59: ...Samsung Electronics 6 6 Exploded Views 6 2 1 Frame Ass y ...
Page 93: ...Electrical Parts List Samsung Electronics 7 12 MEMO ...
Page 97: ...Samsung Electronics 8 4 Block Diagrams MEMO ...
Page 106: ...PCB Diagrams Samsung Electronics 9 9 9 10 Local Talk Service Part s Code JC92 00971A ...
Page 107: ...PCB Diagrams Samsung Electronics 9 10 9 11 Serial IRDA Board Service Part s Code JC92 01116A ...