Philips 32PF9968/10 Service Manual page 18

EN 18 5. LC9.1A LA
• 21: Digital Bolt-on module communication error (where
applicable).
5.4.4 How to Clear the Error Buffer
The error code buffer is cleared in the following cases:
• By using the CLEAR command in the SAM menu:
• If the contents of the error buffer have not changed for 50
hours, the error buffer resets automatically.
Note: If you exit SAM by disconnecting the mains from the
television set, the error buffer is not reset.
5.5 The Blinking LED Procedure
5.5.1 Introduction
The software is capable of identifying different kinds of errors.
Because it is possible that more than one error can occur over
time, an error buffer is available, which is capable of storing the
last five errors that occurred. This is useful if the OSD is not
working properly.
Errors can also be displayed by the blinking LED procedure.
The method is to repeatedly let the front LED pulse with as
many pulses as the error code number, followed by a period of
1.5 seconds in which the LED is "off". Then this sequence is
repeated.
Example (1): error code 4 will result in four times the sequence
LED "on" for 0.25 seconds / LED "off" for 0.25 seconds. After
this sequence, the LED will be "off" for 1.5 seconds. Any RC5
command terminates the sequence. Error code LED blinking is
in red colour.
Example (2): the content of the error buffer is "12 9 6 0 0"
After entering SDM, the following occurs:
• 1 long blink of 5 seconds to start the sequence,
• 12 short blinks followed by a pause of 1.5 seconds,
• 9 short blinks followed by a pause of 1.5 seconds,
• 6 short blinks followed by a pause of 1.5 seconds,
• 1 long blink of 1.5 seconds to finish the sequence,
• The sequence starts again with 12 short blinks.
5.5.2 Displaying the Entire Error Buffer
Additionally, the entire error buffer is displayed when Service
Mode "SDM" is entered. In case the TV set is in protection or
Stand-by: The blinking LED procedure sequence (as in SDM-
mode in normal operation) must be triggered by the following
RC sequence: "MUTE" "062500" "OK".
In order to avoid confusion with RC5 signal reception blinking,
this blinking procedure is terminated when a RC5 command is
received.
2009-Apr-10
Service Modes, Error Codes, and Fault Finding
5.6
5.6.1
5.6.2
5.6.3
Fault Finding and Repair Tips
Notes:
• It is assumed that the components are mounted correctly
with correct values and no bad solder joints.
• Before any fault finding actions, check if the correct
options are set.
Software Protections
Most of the protections and errors use either the stand-by or the
micro processor as detection device. Since in these cases,
checking of observers, polling of ADCs, and filtering of input
values are all heavily software based, these protections are
referred to as software protections.
There are several types of software related protections, solving
a variety of fault conditions:
• Protections related to supplies: check of the 12V.
• Protections related to breakdown of the safety check
mechanism. E.g. since the protection detections are done
by means of software, failing of the software will have to
initiate a protection mode since safety cannot be
guaranteed any more.
Remark on the Supply Errors
The detection of a supply dip or supply loss during the normal
playing of the set does not lead to a protection, but to a cold
reboot of the set. If the supply is still missing after the reboot,
the TV will go to protection.
Protections during Start-up
During TV start-up, some voltages and IC observers are
actively monitored to be able to optimize the start-up speed,
and to assure good operation of all components. If these
monitors do not respond in a defined way, this indicates a
malfunction of the system and leads to a protection.
Hardware Protections
The only real hardware protection in this chassis is (in case of
an audio problem) the audio protection circuit that will trigger
the uP to switch "off" the TV.
Repair Tip
• It is also possible that you have an audio DC protection
because of an interruption in one or both speakers (the DC
voltage that is still on the circuit cannot disappear through
the speakers).
Caution: (dis)connecting the speaker wires during the ON
state of the TV at high volume can damage the audio
amplifier.
NVM Editor
In some cases, it can be convenient if one directly can change
the NVM contents. This can be done with the "NVM Editor" in
SAM mode. With this option, single bytes can be changed.
Caution:
• Do not change these, without understanding the
function of each setting, because incorrect NVM
settings may seriously hamper the correct functioning
of the TV set!
• Always write down the existing NVM settings, before
changing the settings. This will enable you to return to the
original settings, if the new settings turn out to be incorrect.