Service Modes, Error Codes, and Fault Finding
5.
The ComPair faultfinding program is able to determine the
problem of the defective television. ComPair can gather
diagnostic information in two ways:
•
Automatic (by communication with the television):
ComPair can automatically read out the contents of the
entire error buffer. Diagnosis is done on I2C level. ComPair
can access the I2C bus of the television. ComPair can
send and receive I2C commands to the micro controller of
the television. In this way, it is possible for ComPair to
communicate (read and write) to devices on the I2C
busses of the TV-set.
•
Manually (by asking questions to you): Automatic
diagnosis is only possible if the micro controller of the
television is working correctly and only to a certain extends.
When this is not the case, ComPair will guide you through
the faultfinding tree by asking you questions (e.g. Does the
screen give a picture? Click on the correct answer: YES /
NO) and showing you examples (e.g. Measure test-point I7
and click on the correct oscillogram you see on the
oscilloscope). You can answer by clicking on a link (e.g.
text or a waveform picture) that will bring you to the next
step in the faultfinding process.
By a combination of automatic diagnostics and an interactive
question / answer procedure, ComPair will enable you to find
most problems in a fast and effective way.
Beside fault finding, ComPair provides some additional
features like:
•
Up- or downloading of pre-sets.
•
Managing of pre-set lists.
•
Emulation of the Dealer Service Tool (DST).
•
If both ComPair and SearchMan (Electronic Service
Manual) are installed, all the schematics and the PWBs of
the set are available by clicking on the appropriate
hyperlink.
Example: Measure the DC-voltage on capacitor C2568
(Schematic/Panel) at the Mono-carrier.
–
Click on the “Panel” hyperlink to automatically show
the PWB with a highlighted capacitor C2568.
–
Click on the “Schematic” hyperlink to automatically
show the position of the highlighted capacitor.
•
SW upgrading
5.4.3
Stepwise Start-up
This is realised via ComPair and is very helpful when a
protection is activated (see also chapter “Protections”).
Under normal circumstances, a fault in the power supply, or an
error during start-up, will switch the television to protection
mode. ComPair can take over the initialisation of the television.
In this way, it is possible to distinguish which part of the start-
up routine (hence which circuitry) is causing the problem.
Take notice that the transition between two steps can take
some time, so give the set some time to reach a stable state.
During the transition time, the LED can blink strangely.
On activating Service mode, protections and other errors can
be trapped by powering the TV in stepwise fashion as
explained below. The "stepwise start-up" mode is done in the
specified sequence. Before activating this mode, all the
protections are disabled and are only enabled step-by-step, to
trap the errors more appropriately.
The following steps are involved.
Step 0: Standby.
•
Pre-condition: The set is in protection mode.
•
Post-condition: The set is switched to the stepwise start-up
mode. Only the necessary Standby Supply is present, all
other supplies are switched "off".
Step 1: Power "on".
•
Pre-condition: All protections are disabled, sound
amplifiers are muted, and general initialisation is done.
•
Post-condition: 8V and 5V supplies are "on". Degaussing
is "on" and switched "off" after 3 s. The supply fault
protections are enabled.
Step 2: Initialised.
•
Pre-condition: Step 1 is done. No supply protection faults
are detected.
•
Post-condition: ADOC, MPIF, and Tuner components are
initialised.
Step 3: Deflection "on".
•
Pre-condition: Step 2 is done. No protection faults
detected.
•
Post-condition: Deflection is switched "on". The horizontal
deflection fault protections are enabled.
Step 4: TV "on".
•
Pre-condition: Step 3 is done. No protection faults
detected.
•
Post-condition: Picture tube is switched "on". Sound
amplifiers are demuted. The X-ray/beam current fault
protections are enabled.
Note: When the set is in stepwise mode and, due to stepping-
up, a protection is activated, the set will really go into protection
(blinking LED). The set will not leave the stepwise-mode
however. If state X is the state where the set went to protection,
stepwise start-up will return to state X-1. At state (X-1)
diagnostic measurements can be performed. Also, in the short
time, the set is in state X but not in protection, you can also do
some measurements.
5.4.4
How To Connect
1.
First, install the ComPair Browser software (see the Quick
Reference Card for installation instructions).
2.
Connect the RS232 interface cable between a free serial
(COM) port of your PC and the PC connector (marked with
“PC”) of the ComPair interface.
3.
Connect the mains adapter to the supply connector
(marked with “POWER 9V DC”) of the ComPair interface.
4.
Switch the ComPair interface “OFF”.
5.
Switch the television set “OFF” with the mains switch.
6.
Connect the ComPair interface cable between the
connector on the rear side of the ComPair interface
(marked with “I2C”) and the ComPair connector at the rear
side of the TV.
7.
Plug the mains adapter in a mains outlet, and switch the
interface “ON”. The green and red LEDs light up together.
The red LED extinguishes after approx. 1 second while the
green LED remains lit.
8.
Start the ComPair program and read the “Introduction”
chapter.
Figure 5-1 ComPair Interface connection
5.4.5
How To Order
ComPair order codes:
CL96532156_029.eps
190600
PC
VCR
I2C
Power
9V DC
R
L
AUDIO
EXTERNAL 1
EXTERNAL 2
SERVICE
CONNECTOR
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