Technics SX-PR270 M User Manual

ABOUT
THE
SELF-DIAGNOSTIC
FUNCTION
This
model
has
some
self-diagnostic
capabilities.
When
set
to
the
self-diagnostic
mode,
operation
of
various
components
can be verified by
following
the
procedures
in
the
chart
below.
TEST MODE
Procedure
1 | MAIN
RAM (IC6, 8, 9), ROM (IC4, 5)
4.
Connect
the
CHECKING
DEVICE
(refer
to
page
|-15)
to
CN7
on
the
MAIN
P.C.B.,
and
turn
on
the
CHECKING
DEVICE
switch.
2.
Turn
on
the
power
switch.
check
When
the
power
switch
is
turned
on,
the
LED
of
the
CHECKING
DEVICE
flashes
8
times.
The
first
4
flashes
are
for
the
RAM
check,
and
the
latter
4
flashes
are
for
the
ROM
check.
The
order
of
the
LED
flashes
corresponds
to
the
respective
IC
numbers
as
shown
below.
If
an
IC
is
defective,
the
cor-
responding
flash
time
is
longer.
Examples
RAM
ROM
|
|
1 2 3 4 1 2 3 4
1.
RAM
OK,
ROM
OK
———__—>
e
af
e
e
e
e
e
6.3
! 1 1
| { 1
2.
RAM
OK,
ROM
(IC4)
defective
——_—_——-+
©
e
e
@
-
e
e.6.°8
! I 1 i
i i |
3.
RAM
(IC6)
defective,
ROM
OK
—_
@©
@
®
eee
@®e
t et t ft
Icé6 1c8 IC9 IC4 IC5
Note:
@
indicates
short
flash
time=
OK
==
indicates
long
flash
time
=
Defective
V25
gate
array
(IC2)
check
While
pressing
two
C
keys
simultaneously,
turn
on
the
power
switch.
The
contrast
of
the
LCD
(Musical
Display)
on
the
control
panel
changes
in
8
stages.
If
the
contrast
does
not
change,
the
gate
array
(1C2)
is
defective.
3 | CPL
cPSQ
CPR
Control
panel
gate
array
|
1.
Connect
the
CHECKING
DEVICE
to
CN7
on
the
NAIN
P.C.B.
check.
(The
Checking
Device
switch
should
be
off.)
2.
On
the
control
panel,
set
all
the
sliding
BALANCE
controls
to
OFF.
3.
While
pressing
two
D
keys
simultaneously,
turn
on
the
power
switch.
UIT IEA ded ddd
t_1 :
D keys
|
When
the
power
switch
is
turned
on,
the
LED
of
the
CHECKING
DEVICE
flashes
8
times.
The
order
of
the
LED
flashes
corresponds
to
the
gate
arrays
(IC)
on
the
respective
P.C.B.s
as
shown
below.
If
an
IC
is
defective,
the
corresponding
flash
time
is
longer.
There
are
4
flashes
in
the
cyile,
which
is
repeated
once,
totaling
8
flashes.
1 4 1 2 3 4
1.
OK
———_—_>
°
e
eos
@
1
I
2.
CPL
Gate
Array
defective
—————_>
e
-_-
@ @
@
+-@---@
2
e
(
1
i
@
|
|
i
|
CPR P.C.B. Gate Array (IC1|
t
CPSQ P.C.B. Gate Array (IC1)
Note:
@
indicates
short
flash
time=
OK
em
indicates
long
flash
time
=
Defective
!
{
|
|
|
t
CPL P.C.B. Gate Array (IC 1)

Technics SX-PR270 M Specifications

General

Brand	Technics
Model	SX-PR270 M
Category	Musical Instrument
Language	English