Radio Shack TRS-80 26-3650

5-2. Trouble
shooting
Note:
Numbers in CAUSE
column denote order of possibility.
A.
Display
LSI's
to
function
:
CPU,
RAMI
OPERATION
Turn
the
power
switch
on.
Push
the
ALL
RESET
button
on
the
back
of
the
computer.
TROUBLE
Dot
display
cannot
be
shown.
No
display
at
all
or
unusual
indication.
Some
dots
cannot
be
displayed.
RUN
DEG
•
•
•
>
•
•
•
•
•
•
.:
I"-
i::,'
CAUSE
1.
RAMI
2.
CPU
CPU
1.
CPU
2.
LCD
3.
Heat
seal
B.
Key
Entry
LSI's to
function:
CPU
Key input
operation,
Displaying.
RAM 1
Storing
entered
numbers
or
characters.
TROUBLE
No
entry
at
al
Cursor
moves,
but
entered
number
or character
cannot
be
displayed.
Only
characters
can
be entered
CAUSE
t.
CPU
2.
Wiring
between
CPU and
keyboard.
1.
RAMI
2.
CPU
3.
Wiring
between
CPU
and
RAM
1
.
1.
CPU
2.
Wiring
between
CPU
and
keyboard.
-
8