Toshiba 28ZH46P, Service Manual

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8. SELF DIAGNOSTIC FUNCTION
1) Press “9” button on Remote Control during display of adjustment menu in the service mode.
The diagnosis will begin to check if interface among IC’s are executed properly.
2) During diagnosis, the following displays are shown.
23******
POWER
: 00
BUS LINE : OK
BUS CONT : OK
BLOCK
: UV V1 V2
QV01
<SELF CHECK>
Part number of microcomputer (QA01)
Operation number of protecting circuit ----“00” is nor-
mal.
When indication is other than “00”, overcurrent apts to
flow, and circuit parts may possibly be damaged.
BUS LINE CHECK ----“OK” is normal.
“SDA (SDA1)-GND” ----------------------- SDA-GND short circuit.
“SCL (SCL1)-GND” ----------------------- SCL-GND short circuit.
“SCL (SCL1)-SDA(SDA1)” -------------- SCL-SDA short circuit.
BUS CONT ----“OK” is normal.
When indication shows “Q
NG”, the device with
the number may possibly be damaged.
BLOCK
UV : TV reception mode
V1 : VIDEO 1 input mode (
1)
V2 : VIDEO 2 input mode ( 2)
Indicated color of mode now selected : Green and Red
Indicated color of other modes
: White
Green : Normal
Red :
The microcomputer operates to provide judgement
of no video signal. The red color is still indicated
though the signal is input, failure may exist in input
signal line including QV01.
QV01 : In case of indication green ---Normal
In case of indication red with input signal----
Failure may exist in output line including QV01.
*
The items marked with are not usable to display in the SELF DIAGNOSTIC FUCTION for some model.
NOTE: Component which controls character display on
screen is QA01 (MICRO/TELETEXT IC.). If this
display function fails to operate due to damage
of QA01, or QV01 non operation self diagnosis
procedure is as follows.
(1) In case that power indicator is blinking with
interval of 0.5 sec's; it means protecting
circuit is operating, and circuit components
may possibly be damaged. Check related
components.
(2) In case that power in indicator is blinking
with interval of 1 second; protecting circuit
does not operate, but part of bus line does
not operate normally. Check bus line.