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EN 38
5.
BJ3.1A LA
5.8.1
Exit "Factory Mode"
When an "F" is displayed in the screen's right corner, this
means that the set is in "Factory" mode, and it normally
happens after a new SSB has been mounted.
To exit this mode, push the "VOLUME minus" button on the
TV's keyboard control for 5 seconds and restart the set.
When a DVBT TV starts up in factory mode, the TV will tune to
preset 0. When there is no channel installed on preset 0, there
will be no picture and it will look like the set is in standby mode.
De-activating factory mode can also be done via the above
method.
5.8.2
MPIF
Important things to make the MPIF work:
•
Supply.
•
Clock signal from the AVIP.
2
•
I
C from the VIPER.
When there is no sound an external sources, check the audio
supply of the MPIF.
5.8.3
AVIP
Important things to make the AVIP work:
•
Supplies.
•
Clock signal from the VIPER.
2
•
I
C from the VIPER (error 29 and 31).
5.8.4
PACIFIC 3
In case the Pacific fails, the TV will go to stand-by. The reason
for this is, when there is an occasional boot problem of the
Pacific, it will look like the TV has started up in stand-by mode,
and the customer can switch it "on" again. When there is an
actual problem with or around the Pacific the TV will go to
stand-by every time you try to start up. So this behaviour is an
indication of a Pacific problem.
5.8.5
DC/DC Converter
Introduction
•
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 μP is operational.
•
If the input voltage of DC-DC converters is around 12V
(measured on decoupling capacitors 2U17/2U25/2U45)
and the enable signals are low (active) then the output
voltages should have their normal values. First, the
standby μP activates the +1V2 supply (via ENABLE-1V2)
then, after this voltage becomes present and is detected
OK (about 100ms), the other two voltages (+2V5 and
+3V3) will be activated (via ENABLE-3V3). The Vtun
generator (present only for the analogue version of Jaguar
Baby) will generate +33V for the analogue tuner as soon as
the 12V/3.3V DC-DC converter will start operating.
•
The consumption of controller IC 7U00 is around 30mA
(that means around 300mV drop voltage across resistor
3U22).
•
The current capability of DC-DC converters is quite high
(short-circuit current is 7 to 10A), therefore if there is a
linear integrated stabilizer 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 +2V5 supply voltage is obtained via a linear stabilizer
made with discrete components that can deliver a lot of
current, therefore in case +2V5 (or +2V5D) is short-
circuited to GND then +3V3 will not have the normal value
but much less. There is a +2V5D low power linear stabilizer
(to supply the DDR memories in standby mode) that is not
Service Modes, Error Codes, and Fault Finding
used. In normal operation mode the value of this supply
voltage will be close to +2V5 (20..30 mV difference).
•
The supply voltages +5V and +8V6 are available from
connector 1M46; they are not protected by fuses. +12VSW
is protected for over-currents by the fuse 1U04 while 1U01
is protecting in case of defects in DC-DC converters. There
are on-board switches for +8V6-SW (see "DC-DC
CONNECTIONS" schematic) and +12VSW but they are
not used (by-passed).
Fault Finding
•
Symptom: +1V2, +2V5 and +3V3 not present (even for a
short while ~10ms)
1. Check 12V availability (fuse 1U01, resistor 3U22,
power MOS-FETs) and enable signal ENABLE-1V2
(active low),
2. Check the voltage on pin 9 (1.5V),
3. Check for +1V2 output voltage short-circuit to GND that
can generate pulsed over-currents 7...10A through coil
5U03,
4. Check the over-current detection circuit (2U12 or 3U97
interrupted).
•
Symptom: +1V2 present for about 100ms, +2V5 and +3V3
not rising
1. Check the ENABLE-3V3 signal (active LOW),
2. Check the voltage on pin 8 (1.5V),
3. Check the under-voltage detection circuit (the voltage
on collector of transistor 7U10-1 should be less than
0.8V),
4. Check for output voltages short-circuits to GND (+3V3,
+2V5 and +2V5D) that can generate pulsed over-
currents 7...10A through coil 5U00,
5. Check the over-current detection circuit (2U18 or 3U83
interrupted).
•
Symptom: +1V2 OK, +2V5 and +3V3 present for about
100ms. Cause: SUPPLY-FAULT line stays low even
though the +3V3 and +1V2 is available - the standby μP is
detecting that and switching "off" all supply voltages.
1. Check the value of +2V5 and the drop voltage across
resistor 3U22 (they could be too high),
2. Check if +1V2 or +3V3 are higher than their normal
values - that can be due to defective DC feedback of
the respective dc-dc converter (ex. 3U18 or 3UA7).
•
Symptom: +1V2, +2V5 and +3V3 look ok, except the
ripple voltage that is increased (audible noise can come
from the filtering coils 5U00 or 5U03).
Cause: instability of the frequency and/or duty cycle of one
or both dc-dc converters.
1. Check the resistor 3U06, decoupling capacitors, AC
feedback circuits (2U20 + 2U21 + 3U14 + 3U15 for
+1V2 or 2U19 + 2U85 + 3U12 + 3U13 for +3V3),
compensation capacitors 2U09, 2U10, 2U23 and
2U73, IC 7U00.
•
Symptom: +1V2, +2V5 and +3V3 ok, no +Vtun (analogue
sets only). Cause: the "VTUN GENERATOR" circuit
(second schematic) is defective.
1. Check transistor 7U24 (has to have gate pulses of
about 10V amplitude and drain pulses of about 35V
amplitude) and surrounding components.
Note: fuse 1U01 broken means usually a pair of power MOS-
FETs (7U01 or 7U03) defective. The IC 7U00 should be
replaced as well in this case.
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