Hi all.
This set is dead apart for St-By led blinking. Someone told me was a flyback
transformer fault, so I replaced it but subsequently I realized that the
fault wasn't on the deflection section...
The switching seems to work for about 15-20 seconds the shuts down.
While it works, the +5V directed to the digital board is under overload, and
I noticed that the overload depends just by the entire digiboard itself.
Applying a external +5.25 supply, it charges the power supply by more than
1,5A, that seems to be exagerate for those IC. Separating the supply to each
IC of the board, the minimun power required is more than 300-500mA.
Obviously the set rests in protection, even the digiboard controls almost
every section of the set itself. Most of the ICs in the digiboard are the
ITT set for digital treatment of deflection, video, text, teletext code and
color transient, so it seems to be no way to make the set alive.
Could really be a fault of all ICs?
The I2C EEPROM in this board was found completely unusable, even it couldn't
be read or written.
Does anyone experienced a similar fault?
The switching PS seems to work correctly, so I ask you if is possible to
find datasheets or complete schematic of the digital board thus to refer on
it for a deep analisys.
All the ICs seems to be easy to found far a complete reconstruction of the
board, but I would to get the real problem, in order to avoid spending much
money (about 70-100 euros) for a complete revision of the board.
The ICs present in this board a
VCU2136 : video code proc
DTI2223 : transient proc
PVPU2204 : "dunno"
SPU2221 : SECAM proc
DPU2553 : deflection proc
TPU2735 : teletext

and others are
MCU2600: precision oscillator
M3764 : "dunno"
24C0x : EEPROM (found unusable)

Please help me service it, authorized Philips service-center told the
digiboard is obsolet so is impossible to buy it.
I already have original D16-III schematics, Service Manual and common repair
tips for it, but nothing seems to help me...
Anyone have a clue?
Thank you very much to all
Fulcro (Italy)

"Fulcro" ha scritto nel messaggio
...
Hi all.
This set is dead apart for St-By led blinking. Someone told me was a
flyback
transformer fault, so I replaced it but subsequently I realized that the
fault wasn't on the deflection section...
[cut]
Anyone have a clue?

Hi all.
With a deeper analisys, I realized that the SMPS isn't switching correctly,
and doesn't light the lamp connected to the horizontal transistor. so I wold
ask you: it switches correctly only if all charges are connected?
I applyed an external supply for the digiboard and its consumption is abot
1,5A, thus I think that now its time to locate the SMPS problem.
I disconnected all +5V charges (not +5V St-By) and I noticed that 5V is
still absent, so I tested the entire SMPS but it seems to be created just to
make crazy any servician! All tensions at the SMPS secondary are fluctuating
but correct: B+ = 50V in stand-by, +5VSt-By ecc.
What can I test?
Thanks again for any advice, this sets are very rare in my lab....
Fulcro

"Fulcro" ha scritto nel messaggio
...
Hi all.
This set is dead apart for St-By led blinking. Someone told me was a
flyback
transformer fault, so I replaced it but subsequently I realized that the
fault wasn't on the deflection section...
[cut]
Anyone have a clue?

Hi all.
With a deeper analisys, I realized that the SMPS isn't switching correctly,
and doesn't light the lamp connected to the horizontal transistor. so I wold
ask you: it switches correctly only if all charges are connected?
I applyed an external supply for the digiboard and its consumption is abot
1,5A, thus I think that now its time to locate the SMPS problem.
I disconnected all +5V charges (not +5V St-By) and I noticed that 5V is
still absent, so I tested the entire SMPS but it seems to be created just to
make crazy any servician! All tensions at the SMPS secondary are fluctuating
but correct: B+ = 50V in stand-by, +5VSt-By ecc.
What can I test?
Thanks again for any advice, this sets are very rare in my lab....
Fulcro

"Fulcro" ha scritto nel messaggio
...

"Fulcro" ha scritto nel messaggio
...
Hi all.
This set is dead apart for St-By led blinking. Someone told me was a
flyback
transformer fault, so I replaced it but subsequently I realized that the
fault wasn't on the deflection section...
[cut]
Anyone have a clue?

Hi all.
With a deeper analisys, I realized that the SMPS isn't switching
correctly,
[cut]
What can I test?

After a revision, the SMPS seems to work "almost" well, since the +5V are
still absent.
Trying to turn on the deflection, is audible the SMPS that works more for a
second, then backs to Stand-By. All lines output from the SMPS are at a
correct level, either in Stand-By and when the set tryies to start.

141V is present (~60V in St-By mode)
+24 present (~8V in St-By mode)
-24 present (~-8V in St-By mode)
+5V St-By present (since it is stabilized by a 7805, is constant)

The only fault seems to be the +5V line that powers various section:
digiboard, PIP, source select and so on.
What the heck could it be blocking this line?
Just this line is terrible to follow on the schematic!!!
I'm sorry for continue posting on this fault. but is much important and the
D16 chassis seems to have no fault tips document all over the net...
Thank you very very much for any tip.
Fulcro


P.S.: after a minute or so, the SMPS seems to try to go high as deflection
would start, changing the signals from St-By mode to On mode, but this
happens also without pressing any button on RC or TV.

"Fulcro" ha scritto nel messaggio
...

"Fulcro" ha scritto nel messaggio
...
Hi all.
This set is dead apart for St-By led blinking. Someone told me was a
flyback
transformer fault, so I replaced it but subsequently I realized that the
fault wasn't on the deflection section...
[cut]
Anyone have a clue?

Hi all.
With a deeper analisys, I realized that the SMPS isn't switching
correctly,
[cut]
What can I test?

After a revision, the SMPS seems to work "almost" well, since the +5V are
still absent.
Trying to turn on the deflection, is audible the SMPS that works more for a
second, then backs to Stand-By. All lines output from the SMPS are at a
correct level, either in Stand-By and when the set tryies to start.

141V is present (~60V in St-By mode)
+24 present (~8V in St-By mode)
-24 present (~-8V in St-By mode)
+5V St-By present (since it is stabilized by a 7805, is constant)

The only fault seems to be the +5V line that powers various section:
digiboard, PIP, source select and so on.
What the heck could it be blocking this line?
Just this line is terrible to follow on the schematic!!!
I'm sorry for continue posting on this fault. but is much important and the
D16 chassis seems to have no fault tips document all over the net...
Thank you very very much for any tip.
Fulcro


P.S.: after a minute or so, the SMPS seems to try to go high as deflection
would start, changing the signals from St-By mode to On mode, but this
happens also without pressing any button on RC or TV.

--
Attenzione all'indirizzo anti-spam (delay (at) despammed.com)
"Fulcro" ha scritto nel messaggio
...

"Fulcro" ha scritto nel messaggio
...

"Fulcro" ha scritto nel messaggio
...
Hi all.
This set is dead apart for St-By led blinking. Someone told me was a
flyback
transformer fault, so I replaced it but subsequently I realized that
the
fault wasn't on the deflection section...
[cut]
Anyone have a clue?

Hi all.
With a deeper analisys, I realized that the SMPS isn't switching
correctly,
[cut]
What can I test?

After a revision, the SMPS seems to work "almost" well, since the +5V are
still absent.
Trying to turn on the deflection, is audible the SMPS that works more for
a
second, then backs to Stand-By. All lines output from the SMPS are at a
correct level, either in Stand-By and when the set tryies to start.

141V is present (~60V in St-By mode)
+24 present (~8V in St-By mode)
-24 present (~-8V in St-By mode)
+5V St-By present (since it is stabilized by a 7805, is constant)

The only fault seems to be the +5V line that powers various section:
digiboard, PIP, source select and so on.
What the heck could it be blocking this line?
Just this line is terrible to follow on the schematic!!!
I'm sorry for continue posting on this fault. but is much important and
the
D16 chassis seems to have no fault tips document all over the net...
Thank you very very much for any tip.
Fulcro

The set started, but only with an external supply connected to 5V charges
and to (signed) POR2. Now it gives me an error 16 (Nicam I/O Expander) at
video and it probably depends by the 24C04 EEPROM that I replaced and
programmed with binary of other D16 chassis.
The +5V line (not the +5V stand-by) is about 25V (!!!), obviously with no
charges connected, and is present only if I cut the connection to the
(signed) POR2 circuit, otherwise is zero...
What fault could has the (Signed) POR2 line to block the +5V?
Why the +5V line is so high (+about 25V)
Can someone send me the binary file of a Philips D16-III (28DC2070)?
Thanks a lot, and a lot.... but... anyone with a clue?
Fulcro