BLINKING L E D PROCEDURE
- The blinking LED procedure can be split up into two situations:
Blinking LED procedure LAYER 2 error. Via
this procedure, the contents of the error buffer can be made visible via the
front LED. In this case the error contains 2 digits and will be displayed when
SDM (hardware pins) is activated. This is especially useful for fault finding
and gives more details regarding the failure of the defective board.
Important
For an
empty error buffer, the LED should not blink at all in CSM or SDM. No spacer
will be displayed.
When
one of the blinking LED procedures is activated, the front LED will show
(blink) the contents of the error buffer. Error codes greater then 10 are shown
as follows:
The Blinking LED
Procedure
- “n” long blinks (where “n” = 1 to 9) indicating decimal digit
- A pause of 1.5 s
- “n” short blinks (where “n”= 1 to 9)
- A pause of approximately 3 s,
- When all the error codes are displayed, the sequence finishes with a LED blink of 3 s (spacer).
- The sequence starts again
Example: Error 12 8 6 0 0.
After
activation of the SDM, the front LED will show:
- One long blink of 750 ms (which is an indication of the decimal digit) followed by a pause of 1.5 s
- Two short blinks of 250 ms followed by a pause of 3 s
- Eight short blinks followed by a pause of 3 s
- Six short blinks followed by a pause of 3 s
- One long blink of 3 s to finish the sequence (spacer).
- The sequence starts again.
- How to Activate
In case
no picture is shown and there is no LED blinking, read the logging to detect
whether “error devices” are mentioned.
Activate the SDM. The blinking front LED will
show the entire content of the LAYER 2 error buffer, this works in “normal
operation” mode or when SDM (via hardware pins) is activated when the tv set is
in protection.
- Software Protections
Related to supplies: presence of the +5V,
+3V3 and 1V2 needs to be measured, no protection triggered here.
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.
- Supply Errors:
- Protections during Start-up:
- Hardware Protections
- Repair Tip
FAULT FINDING - REPAIR TIPS
- Ambilight
- Audio Amplifier
- AV PIP
- CSM
- DC/DC Converter
The
basic board power supply consists of 4 DC/DC converters and 5 linear stabilizers.
All DC/DC converters have +12V input voltage and deliver:
- +1V1 supply voltage (1.15V nominal), for the core voltage of PNX85500, stabilized close to the point of load; SENSE+1V1 signal provides the DC-DC converter the needed feedback to achieve this.
- +1V8 supply voltage, for the DDR2 memories and DDR2 interface of PNX85500.
- +3V3 supply voltage (3.30V nominal), overall 3.3 V for onboard IC’s, for non-5000 series SSB diversities only.
- +5V (5.15V nominal) for USB, WIFI and Conditional Access Module and +5V5-TUN for +5V-TUN tuner stabilizer
- +1V2 supply voltage (1.2V nominal), stabilized close to PNX85500 device, for various other internal blocks of PNX85500; SENSE+1V2 signal provides the needed feedback to achieve this.
- +2V5 supply voltage (2.5V nominal) for LVDS interface and various other internal blocks of PNX85500; for 5000 series SSB diversities the stabilizer is 7UD2 while for the other diversities 7UC0 is used.
- +3V3 supply voltage (3V3 nominal) for 5000 series SSB diversities, provided by 7UD3; in this case the 12V to 3V3 DC-DC converter is not present.
- +5V-TUN supply voltage (5V nominal) for tuner and IF amplifier.
+3V3-STANDY
(3V3 nominal) is the permanent voltage, supplying the Stand-by microprocessor
inside PNX85500.
Supply
voltage +1V1 is started immediately when +12V voltage becomes available (+12V
is enabled by STANDBY signal when "low"). Supply voltages +3V3, +2V5,
+1V8, +1V2 and +5V-TUN are switched "on" by signal ENABLE-3V3 when
"low", provided that +12V (detected via 7U40 and 7U41) is
present. +12V is considered OK (=>
DETECT2 signal becomes "high", +12V to +1V8, +12V to +3V3, +12V to
+5V DC-DC converter can be started up) if it rises above 10V and doesn’t drop
below 9V5. A small delay of a few milliseconds is introduced between the
start-up of 12V to +1V8 DC-DC converter and the two other DC-DC converters via
7U48 and associated components.- Description DVB-S2:
- +3V3-DVBS (3V3 nominal), +2V5-DVBS (2V5 nominal) and +1V-DVBS (1.03V nominal) power supply for the silicon tuner and channel decoder. +1V-DVBS is generated via a 5V to 1V DC-DC converter and is stabilized at the point of load (channel decoder) by means of feedback signal SENSE+1V0-DVBS. +3V3-DVBS and +2V5-DVBS are generated via linear stabilizers from +5V-DVBS that by itself is generated via the first conversion channel of 7T03.
If +24V drops below +15V level then the DVB-S2 supply will stop, even if +3V3 is still present.
- Debugging
After
ENABLE-3V3 goes "low", all the other supply voltages should rise
within a few milliseconds.
- Tips
- If +12V stays "low", check the integrity of fuse 1U40.
- Check the integrity (at least no short circuit between drain and source) of the power MOS-FETs before starting up the platform in SDM, otherwise many components might be damaged. Using a ohmmeter can detect short circuits between any power rail and ground or between +12V and any other power rail.
- Short circuit at the output of an integrated linear stabilizer (7UC0, 7UD2 or 7UD3) will heat up this device strongly.
- Switching frequencies should be 500 kHz ...600 kHz for 12 V to 1.1 V and 12 V to 1.8 V DC-DC converters, 900 kHz for 12 V to 3.3 V and 12 V to 5 V DC-DC converters. The DVB-S2 supply 24 V to 5 V and 24 V to +V LNB DC-DC converters operates at 300 kHz while for 5 V to 1.1 V DC-DC converter 900 kHz is used.
- Exit “Factory Mode”
- Logging
Required
settings in ComPair before starting to log:
- Start up the ComPair application.
- Select the correct database (open file “Q55X.X”, this will set the ComPair interface in the appropriate mode).
- Close compare
After
start-up of the Hyperterminal, fill in a name (f.i. “logging”) in the
“Connection Description” box, then apply the following settings:
- COMx
- Bits per second = 115200
- Data bits = 8
- Parity = none
- Stop bits = 1
- Flow control = none
During
the start-up of the TV set, the logging will be displayed. This is also the case during rebooting of
the TV set (the same logging appears time after time). Also available in the
logging is the “Display Option Code” (useful when there is no picture), look
for item “DisplayRawNumber” in the beginning of the logging. Tip: when there is
no picture available during rebooting you are able to check for “error devices”
in the logging (LAYER 2 error) which can be very helpful to determine the
failure cause of the reboot. For protection state, there is no logging.
- Guidelines UART logging
UART loggings are displayed:
- When UART loggings are coming out, the first conclusion we can make is that the TV set is starting up and communication with the flash RAM seems to be supported. The PNX85500 is able to read and write in the DRAMs.
- We can not yet conclude : Flash RAM and DRAMs are fully operational/reliable. There still can be errors in the data transfers, DRAM errors, read/write speed and timing control.
- In case there is no UART logging coming out, check if the startup script can be send over the I2C bus (3 trials to startup) + power supplies are switched on and stable.
- No startup will end up in a blinking LED status: error LAYER 1 = “2”, error LAYER 2 = “53” (startup with SDM solder paths short).
- Error LAYER 2 = “15” (hardware cause) is more related to a supply issue while error LAYER 2 = “53” (software cause) refers more to boot issues.
UART loggings reporting fault conditions, error
messages, error codes, fatal errors:
- Failure messages should be checked and investigated. For instance fatal error on the PNX51x0: check startup of the back-end processor, supplies. reset, I2C bus. => error mentioned in the logging as: *51x0 failed to start by itself*.
- Some failures are indicated by error codes in the logging, e.g. => <<<ERROR>>>PLFPOW_MERR.C : First Error (id=10,Layer_1=2,Layer_2=23).
- I2C bus error mentioned as e.g.: “ I2C bus 4 blocked”.
- Not all failures or error messages should be interpreted as fault.For instance root cause can be due to wrong option codes settings => e.g. “DVBS2Suppoprted : False/True. In the UART log startup script we can observe and check the enabled loaded option codes. Defective sectors (bad blocks) in the Nand Flash can also be reported in the logging.
Startup in the SW upgrade application and observe
the UART logging:
Starting
up the TV set in the Manual Software Upgrade mode will show access to USB,
meant to copy software content from USB to the DRAM.Progress is shown in the
logging as follows:
- “cosupgstdcmds_mcmdwritepart: Programming 102400 bytes, 40505344 of 40607744 bytes programmed”.
- Check UART logging in Jet mode mentioned as : “JETT UART READY”.
à COMMAND: calling DFB source = RC6, system=0, key =
4”.
- Loudspeakers
- PSL
- Tuner
Display option code
Attention:
In case the SSB is replaced, always check the display option code in SAM, even
when picture is available. Performance
with the incorrect display option code can lead to unwanted side-effects for
certain conditions.
- New in this chassis: