JVC PD-50X795 Service Manual page 38

5.1 SELF CHECK FEATURE
5.1.1 OUTLINE
This unit comes with the "Self check" feature, which checks the
operational state of the circuit and displays/saves it during
failure.Diagnosis is performed when power is turned on, and
information input to the main microcomputer is monitored at all
time.Diagnosis is displayed in 2 ways via screen display and LED
flashes. Failure detection is based on input state of I
the various control lines connected to the main microcomputer.
5.1.2 HOW TO ENTER THE SELF CHECK MODE
Before entering the Self check Display mode, confirm that the
setting of TV / CATV SW of the REMOTE CONTROL UNIT is at
the "TV" side and the setting of VCR / DVD SW is at the "VCR"
side. If the switches have not been properly set, you cannot enter
the Self check Display mode.
(1) Set to 0 minutes using the [SLEEP TIMER] key.
(2) Press the [VIDEO STATUS] key and [DISPLAY] key
simultaneously, then enter the service mode.
(3) Press the [2] key (SELF_CHK) before the service mode
screen disappears.
(4) Press the [SLEEP TIMER] key to enter Page 2 of the SELF
CHECK MODE.
• When the [RETURN +] key pressed, the first page
change screen.
NOTE:
When a number key other than the [1] to [3] key is
pressed in the SERVICE MODE screen, the other
relevant screen may be displayed.
This is not used in the adjustment procedure. Press the
[MENU] key to return to the SERVICE MENU.
5.1.3 HOW TO EXIT THE SELF CHECK MODE
To Save Failure History:
Turn off the power by unplugging the AC power cord plug when
in the Self check display mode.
To Clear (Reset) Failure History:
Turn off the power by pressing the [POWER] key on the remote
control unit when in the Self check display mode.
5.1.4 FAILURE HISTORY
Failure history can be counted up to 9 times for each item. When
the number exceeds 9, display will remain as 9. Failure history
will be stored in the memory unless it has been deleted.
NOTE:
Only SYNC (with/without sync signals) will be neither counted
nor stored.
1-38 (No.YA100)
SECTION 5
TROUBLESHOOTING
5.1.5 POINTS TO NOTE WHEN USING THE SELF CHECK
FEATURE
In addition to circuit failures (abnormal operation), the following
cases may also be iagnosed as "Abnormal" and displayed and
counted as "NG".
(1) Temporary defective transmissions across circuits due to
pulse interruptions
(2) Misalignment in the on/off timing of power for I
2
C bus and
(VCC) when turning on/off the main power.
Diagnosis may be impeded if a large number of items are
displayed as "NG". As such, start Self check check only after 3
seconds in the case of receivers and 5 seconds in the case of
panels upon turning on the power. If recurrences are expected,
ensure to clear (reset) the failure history and record the new
diagnosis reults.
* As "SYNC" is not counted, the number of failures not displayed.
MAIN MENU SCREEN
SERVICE MENU SERVICE MENU
1.ADJUST 1.ADJUST
2.SELF_CHK 2.SELF_CHK
3.I2C STOP 3.I2C STOP
SELF CHECK MODE SCREEN (Page 1)
LOB LOB OK OK FAN FAN OK OK
SYNC M:OK S:OK HD:NG SYNC M:OK S:OK HD:NG
TIM TIM OK OK
MSM MSM OK OK DIG DIG OK OK
MEM MEM OK OK AVSW OK AVSW OK
YC YC OK OK AIO AIO OK OK
TUN TUN OK OK GCR GCR NG 1 NG 1
IP IP OK OK RGB RGB OK 8 OK 8
DVI DVI OK OK HDMI OK HDMI OK
Item
SELF CHECK MODE SCREEN (Page 2)
FAN FAN OK OK ALM ALM OK OK
TMP TMP OK OK
ATP ATP OK OK ASH ASH OK OK
PNL PNL OK OK MEM MEM OK OK
TMP TMP OK OK AIO AIO OK OK
Item
Fig.1
2
C bus
CHECK
Normality=OK
Abnormality=NG
CHECK
Normality=OK
Abnormality=NG