SONY HCD-ZX66i - ZX99i - COMPONENT Hi-Fi STEREO SYSTEM – Test mode – Cold reset - cd service mode – Audio amplifier schematic diagram - STK412-240M-E - STK412-150C - Audio system repair and service

Category: Audio system Repair and Service 

Contents of this article 

• CD Service mode access 
• Cold reset procedure 
• Power amplifier circuit 

SONY HCD-ZX66i - ZX99i

TEST MODE

GC TEST MODE
# This mode is used to check the fluorescent indicator tube, LEDs, keys, JOG, VOLUME jog, model, destination and software version.
Procedure:
1. Press [FORWARD ] (iPod) button, [TUNING MODE] button and [DISC 2] button simultaneously.
2. All segments in fluorescent indicator tube and the LEDs are lighted up.
3. When you want to enter to the model version and destination display mode, press [DISC 1] button. The model information appears on the fluorescent indicator tube.
4. Each time [DISC 1] button is pressed, the display changes to display software version of the software creation. The sequence is MC, GC, SYS, CD, CDDM, CDMA, CDMB, BDA, BDB, ST, TA, TM, and iPod in this order, and returns to the MC version display.
5. When [DISC 3] button is pressed while the software version is being displayed, the date of the software creation appears. When [DISC 3] button is pressed again, the display returns to the software version display. 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 display.
6. Press [DISC 2] button, the key check mode is activated.
7. In the key check mode, the fluorescent indicator tube displays “K 0 J0 V0”.
Turn the [JOG] clockwise; “J” value increases by one. Turn the [JOG] counterclockwise; “J” value decreases by one. Each time a button is pressed, “K” value increases. Press their keys on main unit to check whether the key is detected. However, once a button has been pressed, it is no longer taken into account. “V” value increases in the manner of 0, 1, 2, 3 ... if [VOLUME] knob is turned clockwise, or it decreases in the manner of 0, 9, 8, 7 ... if [VOLUME] knob is turned counterclockwise.
8. When [EX-CHANGE] button is pressed after all segments in fluorescent indicator tube and the LEDs light up, alternate segments in fluorescent indicator tube would light up. If you press [EX-CHANGE] button again, another half of alternate segments in fluorescent indicator tube would light up. Press [EX-CHANGE] button again would cause all segments lights up.
9. To release from this mode, press three buttons in the same manner as step 1, or disconnect the power cord.

MC TEST MODE
# This mode is used to check operations of the respective sections of Amplifier and Tuner.
Procedure:
# To enter MC Test Mode
1. Press [FORWARD ] (iPod) button, [TUNING MODE] button and [DISC 3] button simultaneously.
2. The CD ring indicators and speaker indicators flash on the fluorescent indicator tube. The function is changed to PHONO.
# Check of Amplifier
1. Press [UP] button and a message “GEQ MAX” appears on the fluorescent indicator tube. GEQ increases to its maximum.
2. Press [DOWN] button and a message “GEQ MIN” appears on the fluorescent indicator tube. GEQ decreases to its minimum.
3. Press either [LEFT] button or [RIGHT] button and a message “GEQ FLAT” appears on the fluorescent indicator tube. GEQ is set to flat.

4. When the [VOLUME] knob is turned clockwise even slightly, the sound volume increases to its maximum and a message “VOLUME MAX” appears on the fluorescent indicator tube.
5. When the [VOLUME] knob is turned counterclockwise even slightly, the sound volume decreases to its minimum and a message “VOLUME MIN” appears on the fluorescent indicator tube.
# To release from MC Test mode
1. To release from this mode, press [POWER] button.
2. The cold reset is enforced at the same time.
COLD RESET
# The cold reset clears all data including preset data stored in the RAM to initial conditions. Execute this mode when returning the set to the customer.
Procedure:
1. Press [FOWARD] (iPod) button, [TUNING MODE] button, and [POWER] button simultaneously.
2. The fluorescent indicator tube becomes blank for a while, and the set is reset.

VACS ON/OFF
# This mode is used to switch ON and OFF the VACS (Variable Attenuation Control System).
Procedure:
1. Press [POWER] button to turn the set ON.
2. Press [AMP MENU] button and [POWER] button simultaneously. The message “VACS OFF” or “VACS ON” appears on the fluorescent indicator tube.

TUNER STEP CHANGE
# The step interval of AM channels can be toggled between 9 kHz and 10 kHz.
Procedure:
1. Press [POWER] button to turn the set ON.
2. Press [TUNER/BAND] button to select the “AM”.
3. Press [POWER] button to turn the set OFF.
4. Press [TUNING MODE] button and [POWER] button simultaneously. The system will turn ON automatically. The message “AM 9k STEP” or “AM 10k STEP” appears on the fluorescent indicator tube and thus the channel step is changed.
CD SERVICE MODE
# This mode let you move the CD sled motor freely. Use this mode when you want to clean the optical pick-up.

Procedure:
1. Press [POWER] button to turn the set ON.
2. Select CD function.
3. Press [FORWARD] (iPod) button, [TUNING MODE] button, and [DISC 5] button simultaneously.
4. The CD service mode is activated. The message “SERVICE MODE” appears on the fluorescent indicator tube.
5. With the CD in stop status, press [FOWARD] (CD) to move the optical pick-up to outside track, or turn [REWIND] (CD) to move to inside track. The message “SLED OUT” or “SLED IN” appears on the fluorescent indicator tube.
6. To turn on or off the laser, press [PLAY MODE] button. The message “LD ON” or “LD OFF” appears on the fluorescent indicator tube.
7. To release from this mode, press [POWER] button.

CD AGING MODE
# This mode can be used for operation check of CD section. If an error occurs, the aging operation would stops and the status is displayed. If there were no error occurs, the aging operation would continue repeatedly.
Procedure:
1. Press [POWER] button to turn the set ON.
2. Select CD function.
3. Load 5 discs on the disc tray.
4. Press [PLAY MODE] button repeatedly to select the “ALL DISCS” mode, and press the [REPEAT] button on the remote repeatedly to select repeat mode off.
5. Press [M] (iPod) button, [TUNING MODE] button and [DISC 4] button simultaneously.
6. Aging operation is started.
7. To release from this mode, press [POWER] button or disconnect the power cord to turn the power OFF.

CD REPEAT 5 LIMIT OFF MODE
# The number of repeat for CD playback is 5 times when the repeat mode is “REPEAT ALL”. This mode enables CD to repeat playback for limitless times.
Procedure:
1. Press [POWER ] button to turn the set ON.
2. Select CD function.
3. Press [FORWARD ] (iPod) button, [TUNING MODE] button and [EX-CHANGE] button simultaneously to enter the CD repeat
5 limit off mode and the fluorescent indicator tube displays “LIMIT OFF”.
4. To release from this mode, operate the cold reset. (Refer to the “MC COLD RESET”)
CD SHIP MODE (WITH MEMORY CLEAR)
# This mode moves the optical pick-up to the position durable to vibration and clears all data including preset data stored in the RAM to initial conditions. Use this mode when returning the set to the customer after repair.
Procedure:
1. Press [POWER] button to turn the set ON.
2. Select CD function.
3. Press [EX-CHANGE] button and [POWER] button simultaneously. The set will power off automatically.
4. After the “STANDBY” blinking display finishes, a message “MECHA LOCK” is displayed on the fluorescent indicator. tube and the CD ship mode is set.
5. Then AC power OFF.
CD SHIP MODE (WITHOUT MEMORY CLEAR)
# This mode moves the optical pick-up to the position durable to vibration. Use this mode when returning the set to the customer after repair.
Procedure:
1. Press [POWER] button to turn the set ON.
2. Select CD function.
3. Press [DISC SKIP] button and [POWER] button simultaneously. The set will power off automatically.
4. After the “STANDBY” blinking display finishes, a message “MECHA LOCK” is displayed on the fluorescent indicator tube and the CD ship mode is set.
5. The AC power OFF.

CD POWER MANAGE
# This mode let you switch on or off power supply to the BU during TUNER function.
# When CD POWER is set to OFF, the power supply to the BU is cut off during TUNER function. It will increase the time taken to access CD when function change from TUNER to CD but it will improve tuner reception.
# When CD POWER is set to ON, the power supply to the BU is not cut off during TUNER function. It will reduce the time taken to access CD when function change from TUNER to CD but it will decrease tuner reception performance.
Procedure:
1. Press [POWER] button to turn the set ON.
2. Select CD function.
3. Press [POWER] button to turn the set OFF.
4. When demonstration appear, press [STOP] (CD) button and [POWER] button simultaneously. The set will power on automatically.
5. The message “CD POWER ON” or “CD POWER OFF” will be displayed on the fluorescent indicator tube.

CD TRAY LOCK MODE
# This mode let you lock the disc tray. When this mode is activated, the disc tray will not open when [OPEN/CLOSE] button or [EX-CHANGE] button is pressed. The message “LOCKED” will be displayed on the fluorescent indicator tube.
Procedure:
1. Press [POWER] button to turn the set ON.
2. Select CD function.
3. Press and hold [STOP] (CD) button and [Z OPEN/CLOSE] button simultaneously until “LOCKED” or “UNLOCKED” displayed on the fluorescent indicator tube (around 5 seconds).
VACS DISPLAY
# This mode is used to check the VACS level.
Procedure:
1. Press [POWER] button to turn on the system.
2. Press [FORWARD] (iPod) button, [TUNER MEMORY] button and [DISC 3] button simultaneously.
3. During the VACS Level Display Mode, the fluorescent indicator tube displays “VACSx APy”. “x” represent VACS level which is triggered by signal level, and “y” represent APVACS (Abuse Protection VACS) level which is triggered.

AUDIO AMPLIFIER SCHEMATIC DIAGRAM 

USING IC STK412-240M-E - STK412-150C

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