JVC PD-42WV74 Service Manual page 55

5.1 SELF-DIAGNOSIS FEATURE
5.1.1 OUTLINE
This unit comes with the "Self-diagnosis" 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-DIAGNOSIS DISPLAY
MODE
(1) Press the [SLEEP TIMER] key and set it to 30 minutes.
(2) Press the [VIDEO STATUS] key and [DISPLY] key
simultaneously, then enter the TEST MODE.
(3) Press the [4] key (Self-diagnosis Display mode) before the
service mode screen disappears.
(4) Press the [MTS] key to enter Page 2 of the Self-diagnosis
Display mode.
*Use the [MTS] key to toggle between Page 1 and Page 2.
NOTE:
The remote control unit attached to this set does not
contain the [MTS] key. To perform the procedure (4), use
a remote control unit that contains the [MTS] key.
5.1.3 HOW TO EXIT THE SELF-DIAGNOSIS DISPLAY MODE
To Save Failure History:
Turn off the power by unplugging the AC power cord plug when
in the self-diagnosis 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-diagnosis 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.
SECTION 5
TROUBLESHOOTING
2
C bus and
* As "SYNC" is not counted, the number of failures is not displayed.
TEST MODE
TEST MODE
1. I2C STOP
2. STATUS DISP.
4. SELF-CHK
Fig.1
<Self-diagnosis Display Mode (Page 1)>
LOB LOB OK OK TIM TIM OK OK
SYNC SYNC M:OK M:OK S:OK S:OK HD:NG HD:NG
MEM MEM OK OK AVSW AVSW OK OK
VCD VCD OK OK BS BS OK OK
AIO AIO OK OK YC YC OK OK
TUN TUN OK OK GCR GCR OK OK
PP PP NG 4 NG 4 IP IP OK OK
Item Item
Diagnosis
Normal = OK
Abnormal = NG
<Self-diagnosis Display Mode (Page 2)>
PNL PNL OK OK
TAM TAM OK OK TMP TMP OK OK
MEMP MEMP OK OK TEMP TEMP OK OK
DDT DDT OK OK DDP DDP OK OK
FAN FAN OK OK AD AD OK OK
DVI DVI OK OK
Fig.2
(No.YA029)1-55