Kenwood NX-220 Service Manual page 44

NX-220
● The LCD displays control *1
Points to be checked
/LCDCS R667
The LCD does not function even if it is exchanged with the Display unit. *1
It is unlikely that the BGA parts are broken.
● When an error display appears on the LCD *1
The LCD displays "ERR 1".
The LCD displays "ERR 2".
The LCD displays "ERR 3".
● When the LED color changes red and orange alternately *2
A warning tone sounds
A warning tone does not sound
*1: C model only
*2: C2 model only
■ Descriptions of signal names
1) RST(RESET) : ASIC reset signal
2) /BINT : Battery fi nal voltage monitoring
3) PSW : Power switch signal
4) /FRST : FLASH reset signal
5) SBC : Switch B control
6) /DRST : DSP reset signal
Replacing TX-RX Unit
■ TX-RX unit Information
Original TX-RX unit
Model Name
NX-220
44
TROUBLE SHOOTING
Normal voltage
3.3V→0V→3.3V
When a normal
value is confirmed.
For Service TX-RX
Number unit Number
X57-8040-10 X57-8040-11
When an abnormal
value is confirmed.
If the /LCDCS is 0V or 3.3V, the ASIC/FLASH/SRAM
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 internal RAM reads
or writes. The SRAM may be broken.
The frequency data was not written.
(Unprogramming)
An error occurs when the ASIC internal RAM reads
or writes. The ASIC may be broken.
or
An error occurs when the DSP internal RAM reads
or writes. The DSP may be broken.
or
An error occurs when the SRAM internal RAM reads
or writes. The SRAM may be broken.
LOW → Reset
LOW → Final voltage
HIGH → ON
LOW → Reset
HIGH → ON
LOW → Reset
■ Method of confi rming "Original TX-RX unit" and
"Service TX-RX unit"
The 0Ω resistor (R4) is mounted
on the "R4" silk print part of the
Service TX-RX unit (X57-8040-11).
R4
X57-804
Component side