TROUBLE SHOOTING
NX-800
43
● When an error display appears on the LCD.
The LCD displays "INIT ERROR1". An error occurs when the ASIC internal RAM reads
or writes. The ASIC may be broken.
The LCD displays "INIT ERROR2". An error occurs when the DSP internal RAM reads
or writes. The DSP may be broken.
The LCD displays "INIT ERROR3". An error occurs when the SRAM internal RAM
reads or writes. The SRAM may be broken.
● Checking the signal output
from the ASIC by software
control
● Panel control (TX-RX unit)
It is unlikely that the BGA parts are broken.
Points to be checked Normal voltage
/PRST R506 (Signal side) 3.3V
When a normal value
is comfirmed.
Points to be checked Normal voltage
SBC R408 3.3V
When a normal value
is comfirmed.
Points to be checked Normal voltage
80C C581 (Signal side) 8.0V
When a normal value
is comfirmed.
When a normal value
is comfirmed.
If the SBC is 3.3V and 80C regulator $IC403 (pin 1)
input side is 8.5V or more, the BGA parts are not broken.
Remove the Q501. If the ASIC side is 0V,
the ASIC/FALSH/SRAM may be broken.
Remove R408. If the ASIC side is 0V,
the ASIC/FALSH/SRAM may be broken.
When an abnormal
value is comfirmed.
When an abnormal
value is comfirmed.
● Panel control (TX-RX unit)
Checking voltage
Points to be checked Normal voltage
5C IC903 (5 pin) 5.0V
33C IC904 (5 pin) 3.3V
Checking the clock/reset
Points to be checked Normal voltage
Xout R948 11.059MHz (5.0V)
/PRST R947 (Signal side) 5.0V
FLASH R986 3.3V
When a normal value
is comfirmed.
When a normal value
is comfirmed.
The BGA parts are not broken.
When an
abnormal
value is
comfirmed.
Checking the Control signal
Points to be checked Normal voltage
/CS0 IC911 (48 pin) 3.3V→0V→3.3V
/RD IC911 (42 pin) 3.3V→0V→3.3V
When a normal value
is comfirmed.
When an abnormal
value is comfirmed.
Checking the Control signal
Points to be checked Normal voltage
/LCDRST R991 (Signal side) 3.3V
/CS3 IC912 (7 pin) 3.3V→0V→3.3V
If nothing is displayed even after replacing the panel,
the BGA may be broken.
The panel microcomputer receives a request of LCD
display from the ASIC. Then, the LCD displays.
The /LCDRST and /CS3 signal become abnormal if
communication is disabled due to a trouble in
the ASIC.
When an abnormal
value is comfirmed.
When an abnormal
value is comfirmed.
When an abnormal
value is comfirmed.
Points to be checked Normal voltage
/DRST R841 3.3V
When a normal value
is comfirmed.
If the /DRST is 0V, the ASIC/FALSH/SRAM are broken.
When an abnormal
value is comfirmed.
When a normal value
is comfirmed.