The blinking LED procedure can be split up into two situations:
• Blinking LED procedure LAYER 1 error.In this case the error is automatically blinked when the TV is put in CSM. This will be only one digit error, namely the one that is referring to the defective board which causes the failure of the TV. This approach will especially be used for home repair and call centres. The aim here is to have service diagnosis from a distance.
• 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 remark:
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:
1. “n” long blinks (where “n” = 1 to 9) indicating decimal digit
2. A pause of 1.5 s
3. “n” short blinks (where “n”= 1 to 9)
4. A pause of approximately 3 s,
5. When all the error codes are displayed, the sequence finishes with a LED blink of 3 s (spacer).
6. 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
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.Blinking LED Procedure
Activate the CSM.
The blinking front LED will show only the latest layer 1 error, this works in “normal operation” mode or automatically when the error/protection is monitored by the Stand-by processor. In case no picture is shown and there is no LED blinking.
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
Most of the protections and errors use either the stand-by microprocessor or the MIPS controller 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:
• 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.
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 optimise 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. As the observers are only used during start-up.
Hardware Protections
The only real hardware protection in this chassis appears in case of an audio problem e.g. DC voltage on the speakers. This protection will only affect the Class D audio amplifier and puts the amplifier in a continuous burst mode (cyclus approximately 2 seconds).
Repair Tip
• There still will be a picture available but no sound. While the Class D amplifier tries to start-up again, the cone of the loudspeakers will move slowly in one or the other direction until the initial failure shuts the amplifier down, this cyclus starts over and over again. The headphone amplifier will also behaves similar.
Fault Finding and Repair Tips
Ambilight
Due to degeneration process of the LED’s fitted on the ambi module, there can be a difference in the color and/or light output of the spare ambilight modules in comparison with the originals ones contained in the TV set. Via SAM => alignments => ambilight, the spare module can be adjusted.
Audio Amplifier
The Class D-IC 7D10 has a powerpad for cooling. When the IC is replaced it must be ensured that the powerpad is very well pushed to the PWB while the solder is still liquid. This is needed to insure that the cooling is guaranteed, otherwise the Class DIC could break down in short time.
AV PIP
To check the AV PIP board (if present) functionality, a dedicated testpattern can be invoked as follows: select the “multiview” icon in the User Interface and press the “OK” button. Apply for the main picture an extended source, e.g. HDMI input. Proceed by entering CSM (push ‘123654’ on the remote control) and press the yellow button. A colored testpattern should appear now, generated by the AV PIP board (this can take a few seconds).
CSM
When CSM is activated and there is a USB stick connected to the TV, the software will dump the complete CSM content to the USB stick. The file (Csm.txt) will be saved in the root of the USB stick. If this mechanism works it can be concluded that a large part of the operating system is already working (MIPS, USB...)
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 PNX855xx, 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 PNX855xx.
• +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.
The linear stabilizers are providing:
• +1V2 supply voltage (1.2V nominal), stabilized close to PNX855xx device, for various other internal blocks of PNX855xx; 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 PNX855xx; 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 PNX855xx. 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:
• LNB-RF1 (0V = disabled, 14V or 18V in normal operation) LNB supply generated via the second conversion channel of 7T03 followed by 7T50 LNB supply control IC. It provides supply voltage that feeds the outdoor satellite reception equipment.
• +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.
At start-up, +24V becomes available when STANDBY signal is "low" (together with +12V for the basic board), when +3V3 from the basic board is present the two DC-DC converters channels inside 7T03 are activated. Initially only the 24V to 5V converter (channel 1 of 7T03 generating +5V-DVBS) will effectively work, while +V-LNB is held at a level around 11V7 via diode 6T55. After 7T05 is initialized, the second channel of 7T03 will start and generates a voltage higher then LNB-RF1 with 0V8. +5VDVBS start-up will imply +3V3-DVBS start-up, with a small delay of a few milliseconds => +2V5-DVBS and +1V-DVBS will be enabled. If +24V drops below +15V level then the DVB-S2 supply will stop, even if +3V3 is still present.
Debugging
The best way to find a failure in the DC/DC converters is to check their start-up sequence at power “on” via the mains cord, presuming that the stand-by microprocessor and the external supply are operational. Take STANDBY signal "high"-to-"low" transition as time reference. When +12V becomes available (maximum 1 second after STANDBY signal goes "low") then +1V1 is started immediately. After ENABLE-3V3 goes "low", all the other supply voltages should rise within a few milliseconds.
Tips
• Behavior comparison with a reference TV550 platform can be a fast way to locate failures.
• 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”
When an “F” is displayed in the screen’s right corner, this means the set is in “Factory” mode, and it normally happens after a new SSB is mounted. To exit this mode, push the “VOLUME minus” button on the TV’s local keyboard for 10 seconds (this disables the continuous mode). Then push the “SOURCE” button for 10 seconds until the “F” disappears from the screen.
Logging
When something is wrong with the TV set (f.i. the set is rebooting) you can check for more information via the logging in Hyperterminal. The Hyperterminal is available in every Windows application via Programs, Accessories, Communications, Hyperterminal. Connect a “ComPair UART”-cable (3138 188 75051) from the service connector in the TV to the “multi function” jack at the front of ComPair II box.
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 ComPair
After start-up of the Hyperterminal, fill in a name (f.i. “logging”) in the “Connection Description” box, then apply the following settings:
1. COMx
2. Bits per second = 115200
3. Data bits = 8
4. Parity = none
5. Stop bits = 1
6. 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.
Description possible cases:
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 PNX855xx 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.
No Uart logging at all:
• 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, check with error codes table (see Table “5-2 Error code overview”).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”.
Startup in Jett Mode:
Check Uart logging in Jet mode mentioned as : “JETT UART READY”. Uart logging changing preset:
=> COMMAND: calling DFB source = RC6, system=0, key = 4”.
Loudspeakers
Make sure that the volume is set to minimum during disconnecting the speakers in the ON-state of the TV. The audio amplifier can be damaged by disconnecting the speakers during ON-state of the set.
PSL
In case of no picture when CSM (test pattern) is activated and backlight doesn’t light up, it’s recommended first to check the inverter on the PSL + wiring (LAYER 2 error = 17 is displayed in SDM).
Tuner
Attention: In case the tuner is replaced, always check the tuner options.
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:
While in the download application (start up in TV mode + “OK” button pressed), the display option code can be changed via 062598 HOME XXX special SAM command (XXX=display option in 3 digits).