Technics SX-PX201

ABOUT THE SELF-DIAGNOSTIC FUNCTION
This modei has some self-diagnostic capabilities. When set to the seli-diagnostic mode, eperaonot of various components can be
veritied by following the procedures in the chart below-*.
No. PCB TEST MODE | fe Procedure
1 MAIN RAM (IC4), ROM (C3) check 1. Connect the CHECKING DEVICE (refer to page I-12) to CN 7 on the
.. MAIN P.C.B., and turn on the CHECKING DEVICE switch,
2. Tum on the power. switch.
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 corresponding
flash time is longer.
Examples 1 RAM 1 F ROM ;
ake 5 er ee a2 AT DS 24
1, RAM OK, ROM OK ————+ @ @@ @ ee @e@
paces ‘ 1
' 1
2. RAM OK, ROM (iC3) defective ————+ @ @ @e©e =~eee
1 1
' '
3: RAM (IC7) defective, ROM.OK : —--—+» = e0@ @e ee ¢e
:
t
=
ae Ice
NOTE : @ indicates short flash time = OK c les
== indicates long flash time’=.Defective
2 MAIN V53 Gate Array (IC2) check Press and hold the two C keys shown below, and then turn on the
power switch.
f 7
it HE i
| ees}
Ckeys
Monitor pins 46-48 {(DL6-DL4) of IC2 on an 45V
4 oscilloscope, and check whether incremental data :
(see figure) is output.
2 od
wef eg ey ony ‘ 058009. .
3° f°" CP» "| Gate array (IC1) check 1 Connect the CHECKING DEVICE to CN 7 on the WAIN P ai B.
(The Checking Device switch should be off).
2. Press and hold the two D keys shown below, and thenturn on the
power switch.
When the power switch is tured on, the LED of the CHECKING DEVICE flashes 4 times. The order of the .
LED flashes corresponds to the CPU (IC) on the respective P.C.B..s as shown below. If an IC is defective,
the corresponding flash time is longer.
i"
4
2.3
4
4,1C1
OK
——+-
ee
ee
1
2.1C1
defective
——---+
m
@
@ ©
NOTE
:
@
indicates
short
flash
time
=
OK
Gate
Array
(§C1)
= indicates long flash time = Defective