HECKING AND ADJUSTMENT
IPower Supply (+5.2)
Make sure that connectors CN1 and CN4 of the power
supply board are firmly connected to CN11 and CN10
of the CPU board, respectively. Note that the Analog
ground path (AG) and Digital ground path (DG) of the
power supply board are electrically indepent of the
1, Turn the S-550 on.
Connect a voltmeter across TP +5(+5.2) and TPDG
of the power supply board.
3. Adjust VR1 of power supply board for +5.5V
reading. If VR1 fails to adjust, refer to the NOTE
NOTE:With products SN below 841699
If VR1 cannot bring the TP+5V to +5.2V, first
check RE for value.
Replace with 30k if the existing value is 27k .
All the products SN 841600 and up have 30k
Turn the S-550 off.
Connect the S-550 to an oscilloscope. Turn the
Holding down 1 button, turn the S-550 on...
keep 1 button until the CRT displays "Please
nsert System Disk".
Insert the utility disk into the disk slot.
When the first access to the disk is complete, press
, and then ~MENU . The utility menu is
from the disk and written into internal
ect "Sampling" from the screen using the cursor
ons and press EXCUTE .
nnect INPUT jack to an audio generator and
y a 3Vpp, 1kHz sine signal.select
LINE using LINE/MIC button. Set REC
EL to MAX.
ect the scope to TPDA (DAC OUT) withground
at TPAG (analog ground).