Trouble Shooting - Kenwood TK-5810 Service Manual

TK-5810 BG
(
Fault diagnosis of the BGA (Ball Grid Array) IC
■ Overview
A fl owchart for determining whether or not the transceiver can be powered on (the LCD does not function even if the power
switch is turned on) due to broken BGA parts.
■ BGA parts
ASIC (IC708), DSP (IC701), FLASH (IC700), SRAM (IC703)
● Checking power supply voltage
Checking voltage
Points to be checked
33M IC2 (5 pin)
15M IC8 (5 pin)
33A IC7 (5 pin)
33BU Q7 (Collector)
Power supply of each device is connected through the ferrite bead.
[ASIC]
33M: L708, 15M: L709
[DSP]
33M: L702, 15M: L701
[FLASH]
33M: L700
[SRAM]
33BU: L703
● Checking the clock
Checking the clock
Points to be checked
18.432MHz ASIC side R764
DSP side R713
32.768kHz IC704 (1 pin)
● Checking the Reset/Control signal
Checking the control signal input to the ASIC
Points to be checked
RESET IC705 (4 pin)
/BINT IC1 (1 pin)
/OVRB D3 (Cathode side)
Checking the ASIC input switch signal
*Each signal is not masked by the setting of the FPU.
The POWER key is pressed and held.
Points to be checked
/PSW Q201 (Drain)
The ignition key is kept ON.
Points to be checked
/IGN (R825)
Points to be checked
/FRST TP991
54
/5810H BG
) ( )

TROUBLE SHOOTING

Normal voltage
3.3V
1.5V
3.3V
3.3V
When a normal
value is confirmed.
Normal voltage (3.3V)
18.432MHz
18.432MHz
32.768kHz
When a normal
value is confirmed.
Normal voltage
3.3V
3.3V
3.3V
When a normal
value is confirmed.
Confirmed voltage
0V
Confirmed voltage
0V
When a normal
value is confirmed.
Normal voltage
3.3V
When a normal
value is confirmed.
Checking for an abnormal point
When an abnormal
value is confirmed.
33M has an abnormal voltage.
[ASIC]
Remove L708 to check the voltage of the 33M.
If the voltage becomes normal, the ASIC is broken.
[DSP]
Remove L702 to check the voltage of the 33M.
If the voltage becomes normal, the DSP is broken.
[FLASH]
Remove L700 to check the voltage of the 33M.
If the voltage becomes normal, the FLASH is broken.
15M has an abnormal voltage.
[ASIC]
Remove L709 to check the voltage of the 15M.
If the voltage becomes normal, the ASIC is broken.
[DSP]
Remove L701 to check the voltage of the 15M.
If the voltage becomes normal, the DSP is broken.
When an abnormal
33A has an abnormal voltage.
value is confirmed.
[ASIC]
Exchange IC7 (33A Regulator) to check the voltage
of the 33A.If the voltage becomes normal, the ASIC
is broken.
33BU has an abnormal voltage.
[SRAM]
When an abnormal
Remove L703 to check the voltage of the 33BU.
value is confirmed.
If the voltage becomes normal, the SRAM is broken.
If the voltage is not corrected, there is a problem
other than the BGA parts.
Remove the R764 and R713. If it oscillates normally,
the DSP and ASIC may be broken.
Exchange IC704 (RTC).If it oscillates normally,
the ASIC may be broken.
The BGA parts are not broken.
When an abnormal
If the /FRST is always 0V, the ASIC is broken.
value is confirmed.
If the /FRST repeats 3.3V and 0V at intervals,
the ASIC, FLASH and SRAM may be broken.