Tait T850 II Series - Serial Communication

B5.10 T855 Fault Finding M850-00
31/09/98 Copyright TEL
5.7.1.2 Serial Communication
Check pin state.
Y
Low/floatin
g
N
Noise
on pin
Disconnect the
pro
g
rammin
g
lead.
Is IC810 pin 11 hi
g
h?
(microcontroller)
Y*di
g
ital stora
g
e
oscilloscope
Use PGM800Win
to send a POLL
command to the
radio.
Check the transistor
interface circuitry
and/or replace the
pro
g
rammin
g
lead.
Check the SERIAL-COM
and AUDIO-1/2 links.
Replace
IC810.
Check the transistor
interface circuitry
and/or replace the
pro
g
rammin
g
lead.
Check the transistor
interface circuitry.
Check IC810 pin 13
with a DSO. Is there
a response from IC810 after
a poll command is sent?
N
Y
Connect the pro
g
rammin
g
lead and use PGM800Win
to read the rack/radio.
Check I/O pad P810
with a DSO*.
Does it swin
g
from
0 to 5V?
N