JVC AV27D302 _ JVC AV27D202 _ SERVICE MODE _ SELF CHECK FUNCTION _MEMORY IC REPLACEMENT _ BLINKING CODES

TO ENTER SERVICE MENU

• Press SLEEP TIMER key and, while the indication of “SLEEP TIMER 0 MIN.” is being displayed, press DISPLAY key and VIDEO STATUS key on the remote control unit simultaneously to enter the SERVICE MENU screen.

SERVICE MENU screen selection

• Press the UP / DOWN key to select any of the following items.

TO ENTER ANY ADJUSTMENT MODE [PICTURE AND SOUND MODE]

1. If select any of PICTURE or SOUND items, and the LEFT / RIGHT key is pressed from SERVICE MENU ( MAIN MENU ), the screen will be displayed.
2. Then the UP / DOWN key is pressed, the PICTURE mode screen or the SOUND mode screen is displayed, and the PICTURE or SOUND setting can be performed.

THEATER, LOW LIGHT AND RF AFC CHECK MODE

1. If select any of THEATER / LOW LIGHT / HIGH LIGHT / RF AFC CHK items, and the LEFT / RIGHT( ) key is pressed from SERVICE MENU ( MAIN MENU ), the screens will be displayed.
2. Then the settings or verifications can be performed.

TO EXIT SERVICE MODE

After returning to the SERVICE MENU upon completion of the setting (adjustment) work, press the EXIT key again.

SELF CHECK FUNCTIONS

This model has self check functions given below. When a malfunction has been detected, the POWER is turned off and the LED flashes to inform of the failure . The malfunction is detected by the signal input state of the control line connected to the microcomputer.

SELF CHECK ITEMS

• CRT NECK PROTECTOR:  Also detected if the power supply line output from the HVT (High voltage Transformer) has shorted with the ground.
• DETAILS OF DETECTION:  When the vertical circuit S correction capacitor C427 is shorted, detect the potential drop of the C427, and prevent the burn damage to the CRT NECK.  (Grounding of shorting of the power supply output from the HVT to the vertical circuit, and the small signal power supply is also detected.)
• METHOD OF DETECTION:  The microcomputer detects at 1 second intervals.  If NG is detected for more than 1 ms, a malfunction is interpreted.
• STATE OF MALFUNCTION:  When a malfunction has been detected, the POWER is turned off. While the POWER is being turned off , the power key of the remote controller is not operational until the power code is taken out and put in again.

SELF CHECK INDICATION FUNCTION

The self-check function begins detection about 5 seconds after power is supplied.  In the event a malfunction is detected, the power is cut off immediately.

At this time, the ON-TIMER LED flashes to inform of the malfunction.

MEMORY IC REPLACEMENT

After replacing the memory IC, system constant check and setting should be done.

• Press SLEEP TIMER key and, while the indication of “SLEEP TIMER 0 MIN.” is being displayed, press DISPLAY key and VIDEO STATUS key on the remote control unit simultaneously.
• The SERVICE MENU screen of Fig.1 is displayed.
• While the SERVICE MENU is displayed, again simultaneously press the DISPLAY and VIDEO STATUS keys to display the SYSTEM CONSTANT screen.
• Refer to the SYSTEM CONSTANT table and check the setting items.  Where these differ, select the setting item with the UP/DOWN  key and adjust the setting with the LEFT/RIGHT keys.
• After adjusting, release the LEFT/RIGHT key to store the setting value.
• Press the EXIT key twice to return the normal screen.