Tait T855 User Manual

M850-00 T855 Fault Finding B5.9
Copyright TEL 31/09/98
5.7 Fault Finding Charts
Note:
The standard test point designations used in this section are as follows:
TP601 13.8V
TP602 9V
TP603 20V
TP604 5V
5.7.1 Microcontroller (IC810)
5.7.1.1 Basic Checks
Pulsing
Check state
of pin 35.
Y
Is pin 30
pulsing?
High or open circuit
Y
Static high/low
Check state of
pins 36 to 43.
Low/floating
High
Is the 12.8MHz clock
present on IC810 pin 21
(microcontroller)?
N
Replace
IC810.
Check IC740
(synthesiser).
*digital storage oscilloscope
Replace IC810.
Check the
state of
pin 10.
N Pulsing
Low
Replace
IC810.
Use a DSO* to check
operation of IC650
(i.e. active high
pulse at power up).
Replace
IC650.
Correct the fault causing
pin 35 to be low/floating.

Tait T855 Specifications

General

Brand	Tait
Model	T855
Category	Accessories
Language	English