Kenwood NX-820H Service Manual page 32

NX-820H(G)/820H
Checking the signal output from
the ASIC by software control
Points to be checked
SBC R407
Points to be checked
/DRST R524
Panel control (TX-RX unit:AVR)
Points to be checked
50C CN412
Points to be checked
80C CN414
Panel control (Disply unit)
Checking the Control signal
Points to be checked
LCDCE CN514 (20 pin)
LCDCL CN514 (21 pin)
LCDDI CN514 (19 pin)
It is unlikely that the BGA parts are broken.
When an error display appears on the LCD.
The LCD displays " ERROR 1".
The LCD displays " ERROR 2".
The LCD displays " ERROR 3".
32
TROUBLE SHOOTING
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
3.3V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
5.0V
When a normal
value is confirmed.
When an abnormal
value is confirmed.
Normal voltage
8.0V
When a normal
value is confirmed.
When an abnormal
Normal voltage
value is confirmed.
5.0V or 0V
When a normal
value is confirmed.
Remove R407. If the ASIC side is 0V,
the ASIC/FALSH/SRAM may be broken.
If the /DRST is 0V, the ASIC/FALSH/SRAM are broken.
If the SBC is 3.3V, when the voltage value of 80C and
50C is abnormal, the BGA parts are not broken.
If Disply unit is removed and a waveform becomes
normal, the BGA parts are not broken.
When a waveform is abnormal, the IC511 may be
broken.
An error occurs when the ASIC internal RAM reads
or writes. The ASIC may be broken.
An error occurs when the DSP internal RAM reads
or writes. The DSP may be broken.
An error occurs when the SRAM reads or writes.
The SRAM may be broken.