Wednesday, February 11, 2015



The Blinking LED
The blinking LED procedure can be split up into two situations:
• Blinking LED procedure in case of a protection. 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 “on” state. Via this procedure, you can make the contents of the error buffer visible via the front LED. This is especially useful for fault finding, when there is no picture. When the blinking LED procedure is activated in the “on” state, the front LED will show (blink)the contents of the error-buffer.
Error-codes > 10 are shown as follows:
1. “n” long blinks (where “n” = 1 - 9) indicating decimal digit,
2. A pause of 1.5 s,
3. “n” short blinks (where “n”= 1 - 9),
4. A pause of approx. 3 s,
5. When all the error-codes are displayed, the sequence finishes with a LED blink of 3 s,
6. The sequence starts again.

1. 1 long blink of 750 ms (which is an indication of the decimal digit) followed by a pause of 1.5 s,
2. 2 short blinks of 250 ms followed by a pause of 3 s,
3. 8 short blinks followed by a pause of 3 s,
4. 6 short blinks followed by a pause of 3 s,
5. 1 long blink of 3 s to finish the sequence,
6. The sequence starts again.
How to Activate
Use one of the following methods:
Activate the SDM or CSM. The blinking front LED will show the entire contents of the error buffer (this works in “normal operation” mode).
Transmit the commands “MUTE” - “062500” - “OK” with a normal RC. The complete error buffer is shown. Take notice that it takes some seconds before the blinking LED starts.
Transmit the commands “MUTE” - “06250x” - “OK”
with a normal RC(where “x” is a number between 1 and 5). When x= 1 the last detected error is shown, x= 2 the second last error, etc.... Take notice that it takes some seconds before the blinking LED starts.
Due to a degeneration process of the Ambi Light, it is recommended to change all ambilight units in case one unit needs to be repaired.
When you activate CSM 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 your USB stick. If this mechanism works you can conclude that a large part of the operating system is already working (MIPS, USB...)

DC/DC Converter
• The best way to find a failure in the DC-DC converters is to check their starting-up sequence at “power-on via the mains cord”, presuming that the standby microprocessor is operational.
• If the input voltage of DC-DC converters is around 12.7V (measured on decoupling capacitors 2U0W and 2U0Y and the enable signals are "low"(active) then the output voltages should have their normal values. +12Vand +5VPOD supplies start-up first(enabled by PODMODE signal from the standby microprocessor). There is a supplementary conditionfor +12V to start-up: if +5V-POD does not start up due to a local defect, then +12V will not be available as well. +5V-ON supply is enabled by the ONMODE signal (coming also from the standby microprocessor) . +1V2 supply starts-up when +12V appears, then at least 100 ms later, +1V8, +2V5 and+3V3 will be activated via theENABLE-3V3 signal from the standby microprocessor. If +12V value is less than 10 V then the last enumerated voltages will not show-up due to the under-voltage detection circuit 7U01-1 + 6U04 and surrounding components. Furthermore, if +12V is less than 8V then also +1V2 will not be available. The third DC-DC convertor that delivers +1V4 out of +12V is started up when the ENABLE-1V2 becomes active (low) and +12V is present. The +Vtun generator (present only for the analogue version of China platforms) will generate +33V for the analogue tuner as soon as the 12V/3.3V DC-DC converter will start to operate.
• The consumption of controller IC 7U0A is around 19 mA (that means almost 200 mV drop voltage across resistor 3U70) and the consumption of controller IC 7U0L is around
12 mA.
• The current capability of DC-DC converters is quite high (short-circuit current is 7 to10 A), therefore if there is a linear integrated stabiliser that,for example, delivers 1.8V from +3V3 with its output overloaded, the +3V3 stays usually at its normal value even though the consumption from +3V3 increases significantly.
• The +1V8 and +2V5 supply voltages are obtained via linear stabilizer made with discrete components that can deliver a lot of current, therefore in case +1V8 or +2V5 are
short circuited to GND then +3V3 will not have the normal value but much less.
• The SUPPLY-FAULT signal (active low) is an internal protection (error 9) of theDC-DC convertor and will occur if the output voltage of any DC-DC convertor is out of limits
(10% of the normal value)
Symptom: +1V2 not present (even for a short while ~10 ms)
1. Check 12 V availability (resistor 3U70, MOS-FETs 7U05 and 7U06), value of +12 V, and surrounding components)
2. Check the voltage on pin 9 (1.5 V),
3. Check for +1V2 output voltage short-circuit to GND that can generate pulsed over-currents 7...10 A through coil 5U00.
4. Check the over-current detection circuit (2U00 or 3U17 interrupted).
Symptom: +1V4 not present (even for a short while ~10ms) while +12V is okay(also across input capacitors
2U8A and 2U8E).
1. Check resistor 3U3T and power MOS-FETs 7U0D-1/2 .
2. Check the voltage on pin 4 (4 V).
3. Check enable signal ENABLE-1V2 (active "low").
4. Check for +1V4 output voltage short-circuit to GND that can generate pulsed over-currents 7...10 A through coil 5U05.
Symptom: +1V2 present for about 100ms, +1V8, +2V5 and +3V3 not rising.
1. Check the ENABLE-3V3 signal (active "low"),
2. Check the voltage on pin 8 (1.5 V),
3. Check the under-voltage detection circuit (the voltage on collector of transistor7U01-1 should be less than 0.8 V),
4. Check for output voltages short-circuitsto GND (+3V3, +2V5 and +1V8) that can generate pulsed over currents
7...10 A through coil 5U01,
5. Check the over-current detection circuit (2U04 or 3U14
Symptom: +1V2 OK, +2V5 and +3V3 present for about 100 ms.Possible cause: SUPPLY-FAULT line stays “low” even though the +3V3 and +1V2 is available - the standby microprocessor is detectingthat and switching "off" all supply voltages.
1. Check the drop voltage across resistor 3U70 or 3U3T (they could be too high, meaninga defective controller IC or MOS-FETs),
2. Check if the boost voltage on pin 4 of controller IC 7U0A is less than 14 V (should be 19 V),
3. Check if +1V2 or +3V3 are higher than their normal values - that can be due to defective DC feedback of the respective DC-DC convertor (ex. 3U1J, 3U75).
Symptom:+1V2, +1V4, +1V8, +2V5 or +3V3 shows a high level of ripple voltage (audible noise can come from the filtering coils 5U00, 5U01 or 5U04).Possible cause:
instability of the frequency and/or duty cycle of a DC-DC converter or stabilizer.
1. Check the resistor 3U0H and 3U2E, capacitors 2U0C and 2U0A, input and output decoupling capacitors.
2. Check a.c. feedback circuits (2U08+2U09+3U07+3U08 for +1V2, 2U8P+2U0Y+3U24 for +1V4 and 2U03+2U05+3U04).
Symptom: +1V2, +1V4, +2V5 and +3V3 ok, no +Vtun (analogue sets only). Possible cause: the “+VTUN GENERATOR” circuit (7U0P +7 U0Q + surroundings components) is defective: check transistor 7U0P (it has to have gate voltage pulses of about 10 V amplitude and drain voltage pulses of about 35 V amplitude) and surrounding components. A high consumption (more than 6 mA) from +Vtun voltage can cause also +Vtun voltage to be too low or zero.
Note: when a pair of power MOSFETs (7U02+7U08, 7U05+7U06 or 7U0D-1/2) becomes defective the controller IC 7U0A or 7U0L should be replaced as well.