6
Fault Condition
No. of Flashes
Multiple TDA884X I²C errors
1
Over voltage / X-ray protection (OVP) 2
Line start-up sequence failed
3
Black current (BC) loop unstable
4
Vertical scan failure
5
Continuous TDA884X power-on reset 6
Multiple error codes may appear, eg. two quick flashes, pause, four quick flashes etc. for OVP + BC loop
errors.
Adjustments
In order to make service adjustments including setting the height, width, various configuration options, etc.,
the TV should have a suitable signal tuned in; ideally, a geometry test card. A teletext signal is
recommended for setting OSD contrast on a teletext chassis.
To enter service mode, place a shorting link across terminals 2 and 3 of P701.
In service mode, two 2-digit hexadecimal numbers are displayed to the left of the screen; the lefthand one is
the service parameter number, the righthand one is the value for that parameter. Some parameters are
identified by a two-letter code instead of a number, see below.
For example:- 0A 1F shows parameter ten (0A hex) at thirty-one (1F hex).
In this mode of operation some of the remote control keys have different functions;
The up and down and local select keys are used to select a parameter.
The remote and local left and right keys are used to change the value of the current parameter.
The TV button is used to store any changes.
The teletext select and digit '0' keys are used for programme up or down.
The Normalize key selects factory picture settings immediately over-writing user settings.
The digit keys '1', '2',----'8' toggle the state of the individual bits '7', '6',----'0' of the value of the current
parameter, for example, pressing digit key '4' would change value 1F hex to 0F hex.
TO STORE THE CHANGES, PRESS THE TV KEY ON THE HAND UNIT BEFORE REMOVING THE
SERVICE MODE LINK. THE MESSAGE 'STORED' WILL BE DISPLAYED TO CONFIRM THE
OPERATION.
Under certain circumstances, for example abnormal operation due to suspected corruption of the service
parameters, it may be necessary to perform a complete reset of the non-volatile memory (
I702
). To effect
this, press and hold the X (teletext update) key for about 3 seconds or until the set switches to standby.
Following this it will be necessary to perform a 'set-up' of the television.
Service Parameters
The following values assume you are watching a tuned in picture, on RF. (On other sources, or with no
signal, some values may differ.)
Service parameters 00 to 1A apply to the control registers of
I501
as shown in the following table.
No.
Value
Function
Action
14"
20"
21"
00
02
02
02
System Control
Do not adjust
01
D0
D0
D0
System Control
Do not adjust
02
1F
1F
1F
Hue (SCART NTSC 4.43 playback only) Use picture menu control instead
03
20
1D
27
Horizontal shift
Adjust to centre picture horizontally
04-07 00
0 0
00
E-W control
Not used on this chassis
08
20
1F
1E
Vertical slope (linearity)
Adjust for vertical linearity
09
10
0B
1A
Height
Adjust for correct picture height
0A
44
4A
4A S-correction
Adjust for best vertical S-correction
