Yamaha DME24N, Service Manual, Page: 82 / 289

82
DME24N/DME64N
DME24N INSPECTIONS
2-1-1. Testing Items and Criteria with Test Program
Perform the testing items No. 01 – 26 in the test
category “01. Product” of the test program and check
if no failure item exists.
Also, perform the testing item No. 27 in the test
category “02. Product(JITTER)” of the test program
and check if no failure item exists.
2-1-2. ANALOG IN /OUT Characteristic Test
2-1-2-1 Settings
· ANALOG IN /OUT Test uses Diag Mode for
measuring.
(Entering to the Diag Mode and its settings will be
described below.)
1. While pressing “ENTER”+“UTILITY”, turn on the
power.
2. Select “01. Product”, and then press the “ENTER”.
3. Select “25. ANALOG IN/OUT” with an “UP”/“DOWN”
key or an encoder, and press the “ENTER”.
4. Select “TEST CASE:#X” with an “UP”/“DOWN” key
or an encoder, and press the “ENTER”.
(#X should be selected depending on the measuring
item.)
5. Check an “OK !” indication on the display.
∗
Inspections the DME24N.
1-1. Measuring Instruments
Measuring instruments to be used should be met the
following conditions.
· 100k
Ω
or Greater Input Impedance.
· 150
Ω
Output Impedance of Oscillator.
· Weighting with LPF at 12.7kHz, -6dB/OCT during
noise measuring.
Measuring should be at average values, not root-
mean-square values.
· Weighting with LPF at 80kHz, -18dB/OCT during the
measuring of total harmonic distortion, signal level,
and crosstalk.
2-1. Inspections by Test Program
Preparation
· Connect a BNC cable to WORD CLOCK IN/OUT.
· Connect a COM terminal connection jig for RS232C/
RS422 loop back test to the REMOTE terminal.
· Connect a special jig for GPI loop back test to the
GPI terminal.
· Connect a MIDI cable to MIDI IN/OUT.
· Insert a MY-SLOT check Ver. 2 test jig into the MY-
SLOT.
· Connect a USB cable with the USB terminal and to a
PC.
Connection Diagram at Test Program Testing
BNC Cable
USB Cable
PC
MIDI Cable
COM Terminal Connection Jig
for RS232C/RS422 Loop Back Test
GPI Inspection
Circuit
DME24N
IN IN/OUT
MIDI
MY-SLOT
IN1-8/OUT1-8
GPI
OUT
USB
WORD CLOCK
REMOTE
MY Slot
Check Jig, Ver.2