HCD-GTZ2, HCD-GTZ2I, HCD-GTZ3, HCD-GTZ3I, MHC-GTZ2, MHC-GTZ2I, MHC-GTZ3, MHC-GTZ3I - Sony Audio Service Manual (repair manual). Page 10

This mode is used to check the fl uorescent indicator tube, LEDs, 
keys, [MASTER VOLUME] jog, [OPERATION DIAL] jog, mod-
el, destination and software version.
Procedure:
1. Press 

[

x

], [METER MODE] and [DISC 2] buttons simultane-

ously.

2.  All LEDs and segments in fl uorescent indicator tube are light-

ed up.

3.  When you want to enter to the software version display mode, 

press [DISC 1] button. The model information appears on the 
fl uorescent indicator tube. “GTL 1” or “GTL 1I” is shown for 
HCD-GTZ2/GTZ2i, “GTL 1S” or “GTL 1SI” is shown for 
HCD-GTZ3/GTZ3i. Press [DISC 1] button again to view the 
destination information.

4.  During the destination information display, press [DISC 1] 

button. Each time [DISC 1] button is pressed, the fl uorescent 
indicator tube shows the version of each category software 
in the following sequence: SC, MTK (DMB board fi rmware 
version), GC, SYS, CD, CDMA, CDMB, ST, TA, TM, MTR 
(METER) and return back to model information display.

5.  When [DISC 3] button is pressed while the version numbers 

are being displayed except model and destination, the date 
of the software creation appears. When [DISC 3] button is 
pressed again, the display returns to the software version dis-
play. When [DISC 1] button is pressed while the date of the 
software creation is being displayed, the date of the software 
creation is displayed in the same order of software version dis-
play.

6.  Press [DISC 2] button, the key check mode is activated.
7.  In the key check mode, the fl uorescent indicator tube displays 

“K 0 J0 V0”.

 

Each time a button is pressed, “K” value increases. However, 
once a button has been pressed, it is no longer taken into ac-
count. 

 

“V” value increases in the manner of 0,1, 2, 3 ... if [MASTER 
VOLUME] knob is turned clockwise, or it decreases in the 
manner of 0, 9, 8,7 ... if [MASTER VOLUME] knob is turned 
counterclockwise.

 

“J” value increases in the manner of 0,1, 2, 3 ... if [OPERATION 
DIAL] knob is turned clockwise, or it decreases in the manner 
of 0, 9, 8, 7 ... if [OPERATION DIAL] knob is turned 
counterclockwise.

8.  When [DISC SKIP/EX-CHANGE] button is pressed after all 

LEDs and segments in fl uorescent indicator tube light up, al-
ternate segments in fl uorescent indicator tube and LEDs would 
light up. If you press [DISC SKIP/EX-CHANGE] button 
again, another half of alternate segments in fl uorescent indi-
cator tube and LEDs would light up.  Pressing [DISC SKIP/
EX-CHANGE] button again would cause all segments in fl uo-
rescent indicator tube and LEDs light up.

9.  To release from this mode, press three buttons in the same 

manner as step 1, or disconnect the power cord.

This mode is used to check operations of the respective amplifi er 
section.

To enter common test mode
Procedure:
1. Press 

[

x

], [METER MODE] and [DISC 3] buttons simultane-

ously.

2.  The CD ring indicators fl ash on the fl uorescent indicator tube. 

The function is changed to PC and the volume is changed to 
VOLUME MIN.

Check of amplifi er
Procedure:
1.  Press [EQ BAND] button repeatedly until a message “GEQ 

MAX” appears on the fl uorescent indicator tube. GEQ increas-
es to its maximum.

2.  Press [EQ BAND] button repeatedly until a message “GEQ 

MIN” appears on the fl uorescent indicator tube. GEQ decreas-
es to its minimum.

3.  Press [EQ BAND] button repeatedly until a message “GEQ 

FLAT” appears on the fl uorescent indicator tube. GEQ is set to 
fl at.

4.  When the [MASTER VOLUME] knob is turned clockwise 

even slightly, the sound volume increases to its maximum and 
a message “VOLUME MAX” appears on the fl uorescent indi-
cator tube.

5.  When the [MASTER VOLUME] knob is turned counterclock-

wise even slightly, the sound volume decreases to its minimum 
and a message “VOLUME MIN” appears on the fl uorescent 
indicator tube.

To release from common test mode
Procedure:
1.  To release from this mode, press [

?/1

 STANDBY] button.

2.  The cold reset is enforced at the same time.

The cold reset clears all data including preset data stored in the 
EEPROM to initial conditions. Execute this mode when returning 
the set to the customer.
Procedure:
1. Press 

[

?/1

 STANDBY] button to turn on the system.

2. Press 

[

x

], [ENTER] and [

?/1

 STANDBY] buttons simultane-

ously.

3.  “COLD RESET” appears on the fl uorescent indicator tube. 

After that, the fl uorescent indicator tube becomes blank for a 
while, and the system is reset.

This mode is used to switch ON and OFF the VACS (Variable At-
tenuation Control System).
Procedure:
1. Press 

[

?/1

 STANDBY] button to turn on the system.

2. Press [

x

], [DISC 2] and [DISPLAY] buttons simultaneously. 

The message “VACS OFF” or “VACS ON” appears on the 
fl uorescent indicator tube.