DHC-EX77MD, DHC-MD77, MDS-EX77, MDS-EX770 - Sony Audio Service Manual (repair manual). Page 4

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This set has no power supply in it, and it does not operate indi-
vidually.  Therefore, connect to the pre/main amplifier system (TA-
EX77) for the DHC-MD77 or DHC-EX77MD in servicing.  If
TA-EX77 is not available, use the power feed jig (PFJ-1) and jig
(J-2501-078-A).  Using the jig, press the power switch (S408) on
the MAIN board in this set to turn on the power.

1. While pressing the CD SYNC + CONTINUE buttons simul-

taneously, insert the power cord of TA-EX77 (pre/main am-
plifier) into the power outlet, then release the buttons.  (Thus,
the check mode is activated.)

2. When buttons are released, “Key Check” is displayed for a

moment, then fluorescent indicator tubes are all turned on.
(LED for ANALOG IN indication is also turned on.)

3. As the buttons other than CD SYNC  are pressed, fluores-

cent indicator tubes, one block each, are turned off, and all
tubes are off when operation of all buttons (except CD SYNC
button) is finished.  (ANALOG IN LED is turned off when  

p

button is pressed.)

4. Press the CD SYNC button with fluorescent indicator tube

in all off status, “Key TEST OK!” is displayed for a moment,
then “JOG&LEDCheck” is displayed.  (At this time,
if REPEAT button is pressed, “STANDBY” is displayed and
blinking, implying that normal operation is ready.)

5. With “JOG&LEDCheck” displayed, turning the SELECTOR

konb, and all LEDs simultaneously turn on and off repeatedly.
(If REPEAT button is pressed, normal operation is ready.)

6. With “JOG&LEDCheck” displayed, press the CD SYNC button,

and “SegmentCheck” is displayed for a moment, then segment
display is made.  (If REPEAT button is pressed, normal op-
eration is ready.)

7. Press the CD SYNC button, and “end” is displayed.  Then,

press the REPEAT button to finish the check mode.

With the power turned on, turning the  SELECTOR  konb while
pressing the  

p  button to select either of the following:

Analog in
Digital 1 in
Digital 2 in

P707,909
CDP/TC

Power feed jig
       (PFJ-1)

SYSTEM CONTROL connector

set

jig

(J-2501-078-A)

connector cable (17P)

(attached to the PFJ-1)

connector cable (7P)
 (attached to the set)

CN904

(17P)

CN902

(7P)

CN501 (7P)

(S408)

Power switch