Technics SX-KN901

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.
[No | POB. | = TESTMODE =| Procedure
RAM (1C4-6), ROM (IC7-9) | 1.Connect the CHECKING DEVICE (refer to page I-14) to CN 1 on the
check MAIN P.C.B., and turn on the CHECKING DEVICE switch.
2.Turn 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
correspond to the respective IC numbers as shown below. If an IC is defective, the corresponding flash
time is longer. :
RAM ROM
Examples
| |
1. RAM OK, ROM OK
.2. RAM OK, ROM (IC8) defective
@ ---] ---e-
@---@---enr
@---@---@ 8
3. RAM (IC5) defective, ROM OK
Q —> fo)
OQ —>
oO
os Ni SG @---@---@8
O— @---@---@p Q e e e & eee leita eat Di
NOTE: @ indicates short flash time
ma indicates long flash time
Control panel CPU check 1.Connect the CHECKING DEVICE to CN 1 on the MAIN P.C.B.
(The Checking Device switch should be off).
2.Press and hold the two D keys shown below, and then turn on the
power switch.
TTL
D keys
When the power switch is turned 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.
2. CPU defective
NOTE: @ indicates short flash time
m= indicates long flash time