Philips 42PFL7403D Doesnt turn on

[pacmyc]

Originally Posted by pacmyc

OK. The only 1000 µF I've got is a 35 V.
Is it allright to replace with this one?

Replaced, no difference.
Could someone help me to confirm that it's really the PSU that is faulty? I dont want to spend another 100$ on another PSU and fint out that it's the main-board that's broken...

[Nightwalker]

Hello everyone

A friend bring me a same TV with the same problem. Began 2 months ago, shut down by itself after a while and after 2-3 hours was operational again. Since 1 week, TV was completed dead and never power up again, so yesterday bring it to me.

Symptoms are like PACMYC's problem:
1.Disconnecting the IR LED connector -> PSU relay click
2.With connected IR LED, PSU relay do nothing
3.PIN 5 voltage is 3.3 steady when is not connected, 3.0-3.2 flashing when its connected.

At service manual says at page 27:

Error 18 (1V2-3V3-5V too low). All these supplies are
generated by the DC/DC supply on the SSB. If one of these
supplies is too low, protection occurs and blinking LED
LAYER error 1 = 2 will be displayed automatically. In SDM
this gives LAYER error 2 = 18.

But at connector 1M95, pin1 PSU side creates a 3.4 V stable when connector is disconnected and 3.0-3.2 when its connected.

I think that SSB board is faulty, not PSU or IR LED board, something had to do with software protection of this board and 3V3 standby power nor signal.

Any ideas?

[pacmyc]

Originally Posted by Nightwalker

Hello everyone

A friend bring me a same TV with the same problem. Began 2 months ago, shut down by itself after a while and after 2-3 hours was operational again. Since 1 week, TV was completed dead and never power up again, so yesterday bring it to me.

Symptoms are like PACMYC's problem:
1.Disconnecting the IR LED connector -> PSU relay click
2.With connected IR LED, PSU relay do nothing
3.PIN 5 voltage is 3.3 steady when is not connected, 3.0-3.2 flashing when its connected.

At service manual says at page 27:

Error 18 (1V2-3V3-5V too low). All these supplies are
generated by the DC/DC supply on the SSB. If one of these
supplies is too low, protection occurs and blinking LED
LAYER error 1 = 2 will be displayed automatically. In SDM
this gives LAYER error 2 = 18.

But at connector 1M95, pin1 PSU side creates a 3.4 V stable when connector is disconnected and 3.0-3.2 when its connected.

I think that SSB board is faulty, not PSU or IR LED board, something had to do with software protection of this board and 3V3 standby power nor signal.

Any ideas?

Still no replies on this one..
Just be careful when testing with connector 1M95 disconnected, see my post #54

I ran the TV with the 3V3 stdby line to led panel control disconnected (without reconnecting it after the TV has started).. Something must have happened because I now I cant start the TV at all.
The background light lits up for a second and then TV goes dead.

If you find out anything useful please update me on it..

[schlickbert]

hi there,

i just tripped upon this thread, having the exact same problem with my 7403.

could you fix your "problem" by now? and if so, how?

thanx and best regards!

schlickbert (new member / first post)

[Nightwalker]

Hello

Still nothing from me, the only findings are (dont remember where i read it) :

Fee Q529.1E SSB used in many LCD TVs PHILIPS, but, unfortunately, 
in the past, they have become massively fail. The cause of their damage 
are substandard planar transistors. The purpose of these field-effect 
transistors is stabilized power supply (1.2 V, 2.5 V and 3.3 V) for the 
different controllers. Most often burned transistors responsible for 3.3 volts, 
transistor after 95% of the crashes controller PNX. The repair of these boards 
complex and not always a positive result, and we urge you not to try to repair 
themselves. For the repair of this unit requires the IR station, stencils, balls ...
So the problem is shown in LCD TVs PILIPS in case of failure of payment SSB Q529.1E

1. TV does not turn on, blinks 3 or 2 times

2. TV does not turn on the red light

3. Stripes on the screen, the sound is normal

The easy think is to find and change transistors, but i havent found PNX BGA on market yet..so i still searching..

[pacmyc]

Hi. Sorry same here, no news.
Im giving up on this one as long as I dont get any tips of things to try.

[schlickbert]

hi again,

maybe i should have read this thread more carefully. after measuring and experimenting, i finaly changed capacitor "2170" to 1000uF 25V on the main power supply.

until now everything seems to be working fine for me to ........ :-)

best regards
schlickbert

[pacmyc]

Originally Posted by schlickbert

hi again,

maybe i should have read this thread more carefully. after measuring and experimenting, i finaly changed capacitor "2170" to 1000uF 25V on the main power supply.

until now everything seems to be working fine for me to ........ :-)

best regards
schlickbert

Hi.
What do you mean? Is the TV now working??

[schlickbert]

well,........

it was working as long as i dindn´t touch that fu...ing keyboard panel.......

now i inserted a delay circuit wich delays the ir/led board´s 3.3V from "sucking" immediately. this gives the power supply enough time to power up normally.

i know, this is not how it´s supposed to be done, but it works. the keyboard panel stil has some malfunctions, but i don´t care about that.