Panasonic KX-F680BX - Page 57

|62 |
KX-F680BX/KX-F2681BX
The graphs below show you the wave form that is observed when unit (board) doesn't work. (A3 is intentionally opened at
pin 135 of ASIC in this board.)
Please check that active (low level) term of ROMCE is longer than good wave form, **ROMCE is active (low level) except-
ing RESET is active.** and RESET is frequently coming on every 4 msec.
In the case of this wave form ASIC (IC1), ROM (IC2) or on the way of bus line route is possibly defect. If soldering, con-
ductance is no problem, we need to replace these ICs.
CH1 5V/div
CH2 5V/div
CH3 5V/div
CH4 5V/div
W1 500ns/div
Length 100
W2 5µs/div
Length 1k
Sampling
Normal
20Msps
Marker 1
T 9.65µs
V 4.7 V
Marker 2
T 7.50µs
V 4.9 V
T -2.15µs
1/ T
465.1k Hz
V 0.2 V
W1 500µs
W2 5µs
Position
W1 6.20µs
W2 25.00µs
Time
Time Base Roll
Off
Time Base
External
Internal
Internal
-39.9V
6.20µs 11.20µs
Time/div
10.0V
H1 W1
A0
D0
ROMCS
RD
NG
Trigger CH1/2 MEM1 MEM2
Too long
CH1 5V/div
CH2 5V/div
CH3 5V/div
CH4 5V/div
W1 1ms/div
Length 100
W2 10ms/div
Length 1k
Sampling
Normal
10ksps
Marker 1
T 576.5ms
V 4.8 V
Marker 2
T 15.0ms
V 0.2 V
T -561.5ms
1/ T
1.781 Hz
V -4.6 V
W1 1ms
W2 10ms
Position
W1 575.0ms
W2 50.2ms
Time
Time Base Roll
Off
Time Base
External
Internal
Internal
-40.0V
575.0ms 585.0ms
Time/div
10.0V
H1 W1
A0
D0
ROMCS
RST
RESET RESET
NG
Trigger CH1/2 MEM1 MEM2
Too long