Hitch Diagnosis Based On The Display Condition - Sony PFM-42X1 Service Manual

2-4-2. Hitch Diagnosis Based on the Display
Condition
1. 4/7 or 3/7 of the screen is not displayed
1) Check if the power connector of the X B/D that
corresponds to the screen portion with no picture is
securely connected.
2) Check whether the connector that connects the CTRL
B/D and the X B/D that correspond to the screen
portion with no picture is securely connected.
3) Replace the corresponding X B/D.
Relationship between the screen and X B/D
Screen
Left 4/7 portion of the screen
Right 3/7 portion of the screen
Screen display forms
Left of the screen (4/7) Right of the screen (3/7)
Displayed
Not displayed
2. Data COF is not shown on screen (Including
the case where a part of Data COF is not
shown)
1) When Data COF is not shown, in many cases a
problem resides between Data COF and the X B/D.
2) Check if the Data COF and the X B/D that correspond
to the screen portion with no picture are securely
connected.
3) Check if the Data COF is not damaged, and replace the
X B/D.
Examples of the screen display form
(Any one of the 7 Data COF can be seen next to the below
pictures.)
PFM-42X1/42X1N
. Change "1 GND" into ANODE, "2 Resistance" into
X B/D
↔
Right X B/D
. Measure the resistance value (10 Ω).
↔
Left X B/D
3. An unusual pattern corresponding to the Data
1) If an unusual pattern corresponding to the Data COF
2) In the case of <Case 1, 2, 3>
3) In the case of <Case 4, 5>
<Case 1>
<Case 2>
<Case 3>
<Case 4>
: All
<Case 5>
: Partial
: Not at all
How to examine Data COF IC
2 Resistance
CATHODE, and then examine the diode in the forward
or backward direction.
COF IC unit is shown
IC unit is displayed as shown below, the input to the
Data COF IC has a problem.
. Check the connection of the Data COF connector.
. Replace the corresponding X B/D.
. Check the connector that connects the CTRL to the
X B/D.
. Replace the corresponding XB/D or CTRL B/D.
Screen display forms
1 GND
An unusual screen that
corresponds to one IC
appears in one COF.
An unusual screen that
corresponds to two ICs
appears in one COF.
An unusual screen that
corresponds to four ICs
appears in one COF.
An unusual screen that
corresponds to one Data
COF IC unit appears in
an entire X B/D.
An unusual screen that
corresponds to one Data
COF IC unit appears in
the entire upper or lower
part of the screen.
2-9