Philips FTV1.9EE Service Manual Download

Page: 26 / 87

Service modes, fault finding and repair tips

GB 26

FTV1.9EE

5.5

Fault-finding tips

5.5.1

Supply E-box

The E-box power supply is a Switch Mode Power Supply
(SMPS) with a current regulating pulse width modulator IC1-
UC3843. The topology is a flyback converter with primary
current sensing, secondary voltage sensing and mains input
measuring.
The SMPS works in discontinuous mode, so with a T-on, T-off
and a T-dead.
The E-box supply delivers the following output voltages:
•

5V_stb (SSP

µΠ

& Control, Euro I/O, AV Buffer, Led panel

and front I/O) : + 5V1 This voltage is also present during
standby.

•

5V2 (SSP, FBX 4, Euro NICAM, AV Buffer, DW and TXT
panel) : + 5V3

•

8V6 (SSP, and Euro I/O panel) : 8V6

•

+12V8 (SSP, Incredible Stereo (AY), FBX 4, Euro NICAM,
AVB and DW) : 12V8

•

+33 V (SSP-frontend, DW) : 40 V

To trouble shoot the E-box Supply, first check the LED of the
E-box:
•

No red or green LED indicates the absence of the +5Vstby
at the Front I/O panel.
–

Check the +5Vstby voltage on C54.

–

If the +5Vstby voltage is present, check fuse F4 at the
secondary side. If fuse F4 is OK, check/replace item
6002 at the LED-panel E-box together with connector

AV15 at the front I/O and connector LE15 at the LED-
panel E-box.

–

If +5Vstby is not present at C54, check the voltage at
capacitor C60. Is this voltage approx. 300 Vdc (Mains-
voltage is 230 Vac) If the voltage is not present check
fuse F1, NTC resistor R3 and the diodes D1- D4 at the
primary side. If the voltage is present at C60, measure
the waveform at pin 5 of IC4. If the measured
waveform equals the problem might be caused by a
defective transformer TR1, diode D25 or coil L6. If the
voltage at pin 5 of IC4 is approx. 300 V (Vmain = 230
Vac) then check/replace IC4, transistor T5 and opto-
coupler OC3-B at the primary side or regulator IC3 and
transistor T6 at the secondary side. In case fuse F1 is
open, check/replace in this case IC4 for the standby
supply but also IC1 and MOSFET T1 with in series the
parallel-resistors R11 and R12. In case of a defective
MOSFET T1 check also resistor R8 + R9 and diode
D10.

•

The red LED is blinking (+5Vstby is OK!), which is an
indication of a protection.
–

Switch OFF the Monitor if connected to the E-box.

–

Read out the contents of the error-buffer via "Diagnose
x OK".

–

Content of the error-buffer contains 44, which means a
failure of the 5V2. Check/Replace in this case
fuse F2 and F3 close to connector SU10. See also
supply diagram E-box, for an overview of the panels
that are supplied with 5V. Check each panel which is
supplied with the +5V2.

–

Remove connector SU10 and SU02. (Caution!! -
Protection switched off) Measure the voltages at
capacitor C26 of the 12V8 supply and capacitor C30 of
the 5V2 supply.

–

If the voltages are correct than one of the outputs was
over-loaded/short circuited due to a failure on a panel.
See also supply diagram E-box, for an overview of the
supply to the panels.

–

If the voltages are not correct, there is a failure in the
power-supply E-box.
–

The problem could be caused by +5V regulation-
circuit at the secondary side, which is built around
opto-coupler OC2 and regulator IC2. Measure Fb1
and measure wave-form . The voltage at Fb1
should be approx. 3.5V. If not OK, check both
components and replace if necessary.

–

Check voltage at pin 7 of IC1.

–

If this voltage is below 8V5 then check for the
+12Vstby and opto-coupler OC1. In case the
+12Vstby is below 8V5 check diode D22 or
capacitor C50. Is the +12Vstby above 8V5 then
check opto-coupler OC1 together with transistor
T2 + T3 and diode D14 + D15 at the secondary
side and transistor T4 and diode D5 at the primary
side. If no. check/replace IC1.

–

Measure the wave-form at pin 6 and compair it to
P2. If the wave-form does not match test-point P2,
check resistor R8 + R9, diode D10 and MOSFET
T1.

5.6

ComPair

5.6.1

Introduction

ComPair (Computer Aided Repair) is a service tool for Philips
Consumer Electronics products. ComPair is a further
development on the DST service remote control allowing faster
and more accurate diagnostics. ComPair has three big
advantages:

Error
code

Description

Others

Non Volatile Memory

24C16

IF (SSP)

FQ916ME

10 / 11

Audio matrix (Eco Euro I/O)

TEA6430

Toshiba mP (Eco Euro I/O)

TMP47C443N