Philips 26MF231D/37, Service Manual

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TPE1.0U LA
5. Service Modes, Error Codes and Fault Finding
access the I C/UART bus of the television. ComPair can
send and receive I C/UART 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 I C/UART buses 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 extend.
When this is not the case, ComPair will guide you through
the fault finding tree by asking you questions (e.g.
) and showing you examples (e.g.
). 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 fault finding 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.
5.4.3 How to Connect
This is described in the chassis fault finding database in
ComPair.
Caution: It is compulsory to connect the TV to the PC as
shown in the picture below (with the ComPair interface in
between), as the ComPair interface acts as a level shifter. If
you connect the TV directly to the PC (via UART), the VIPER
or PNX2015 will be blown!
Does the
screen give a picture? Click on the correct answer: YES /
NO Measure test-point I7
and click on the correct oscillogram you see on the
oscilloscope
2
2
2
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UART SERVICE
CONNECTOR
TO
I C SERVICE
CONNECTOR
2
Fig. 5-2 ComPair interface connection
5.4.4 How to Order
ComPair order codes (US):
ComPair Software: ST4191.
ComPair Interface Box: 4822 727 21631.
AC Adapter: T405-ND.
ComPair Quick Start Guide: ST4190.
ComPair interface extension cable: 3139 131 03791.
ComPair UART interface cable: 3122 785 90630
: If you encounter any problems, contact your local
support desk.
5.5.1 Introduction
The error code buffer contains all detected errors since the last
time the buffer was erased. The buffer is written from left to
right, new errors are logged at the left side, and all other errors
shift one position to the right.
When an error has occurred, the error is added to the list of
errors, provided the list is not full or the error is a protection
error.
When an error occurs and the error buffer is full, then the new
error is not added, and the error buffer stays intact (history is
maintained), except when the error is a protection error.
To prevent that an occasional error stays in the list forever, the
error is removed from the list after 50+ operation hours.
Note
5.5 Error Codes
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When multiple errors occur (errors occurred within a short time
span), there is a high probability that there is some relation
between them.
Basically there are three kinds of errors:
. These
errors will always lead to protection and an automatic start
of the blinking LED for the concerned error (see paragraph
The Blinking LED Procedure ). In these cases SDM can
be used to start up (see chapter Stepwise Start-up ).
. In this case
the TV will go to protection and the front LED will blink at 3 Hz.
Further diagnosis via service modes is not possible here (see also
paragraph Error Codes -> Error Buffer -> Extra Info ).
. In this
case the error can be read out via ComPair, via blinking LED
method, or in case you have picture, via SAM.
5.5.2 How to Read the Error Buffer
Use one of the following methods:
On screen via the SAM (only if you have a picture). E.g.:
- 00 00 00 00 00: No errors detected
- 06 00 00 00 00: Error code 6 is the last and only
detected error
- 09 06 00 00 00: Error code 6 was first detected and
error code 9 is the last detected error
Via the blinking LED procedure (when you have no
picture). See next paragraph.
Via ComPair.
5.5.3 How to Clear the Error Buffer
Use one of the following methods:
By activation of the RESET ERROR BUFFER command
in the SAM menu.
With a normal RC, key in sequence MUTE followed by
062599 and OK .
If the content of the error buffer has not changed for 50+
hours, it resets automatically.
5.5.4 Error Buffer
In case of non-intermittent faults, clear the error buffer before
you begin the repair (before clearing the buffer, write down the
content, as this history can give you significant information).
This to ensure that old error codes are no longer present.
If possible, check the entire contents of the error buffer. In
some situations, an error code is only the result of another error
code and not the actual cause (e.g., a fault in the protection
detection circuitry can also lead to a protection).
There are several mechanisms of error detection:
Via error bits in the status registers of ICs.
Via polling on I/O pins going to the stand-by processor.
Via sensing of analogue values on the stand-by processor.
Via a not acknowledge of an I C communication.
Take notice that some errors need more than 90 seconds
before they start blinking. So in case of problems wait 2
minutes from start-up onwards, and then check if the front LED
is blinking.
5.6.1 Introduction
The blinking LED procedure can be split up into two situations:
Blinking LED procedure in case of a protection detected by
the stand-by processor. In this case the error is
automatically blinked. This will be only one error, namely
the one that is causing the protection. Therefore, you do
not have to do anything special, just read out the blinks. A
long blink indicates the decimal digit, a short blink indicates
the units.
Blinking LED procedure in the
state. Via this
procedure, you can make the contents of the error buffer
Errors detected by the Stand-by Processor
Errors detected by VIPER that lead to protection
Errors detected by VIPER that do not lead to protection
5.6 The Blinking LED Procedure
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"ON"
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