Philips LCD 42 inch TV (42PFL7403D/10) dead

[pacmyc]

Philips LCD 42 inch TV (42PFL7403D/10)
Chassis Q529 1E LA.

TV only power on sometimes. I opened it, took ut the PSU to look for bad capacitors. I found nothing. Fit it back together and now it doesn't power up at all. When connected to mains nothing happens. When pressing buttons on remote control the red led on the front side flashes shortly once each time i press a button.

I checked the voltages on the PSU, and I got nothing except on the standby 3.3V. It was "flashing" (cheap multimeter) between 3.06 V - 3.25 V (service manual says should be 3.3 V). When pressing a button on the remote control the standby voltage drops to about 2,6 V for about a second, and then goes back to 3.06 - 3.25 V.

I tried uploading the servicemanual into the download section but it failed.
It will be downloadable at http://wtrns.fr/W5wgp1S83waVjz0 until 2:nd of August.

[Turnip]

Hi Rasmus,

Got your manual as suggested and tried to upload to Quuq - failed, after half an hour, as your's did.

Put a query in Quuq  'Anything else' - All the best - Chris.

[pacmyc]

Hi Chris.

OK thanx. I bought some capacitors that I will try to replace today.
Just a newbie question; I saw that on the top of the capacitors there is a letter punched into the metal.
I've notices that there are a "X", a "K" or a "T". I have never noticed this before!

Is it important to replace a capacitor with one with the same letter? (Capactiance and voltage are correct).
(All are electrolyte)

[pacmyc]

I managed to turn on the TV once again. When mains were connected the blue standbylight lit up, and I was able turn the TV ON. I checked for error messegaes in SAM mode but the list was empty.
Turn off the TV with the remote, and now I cant turn it back on.

Also operation hours say 11000 hours! Wow this TV has been used a lot. In servicemanual it says that everytime you turn the TV on, 0,5 hours will be added to operation hours. Maybe when I have been trying to turn the TV on many times multiple hours have been added..


Please any ideas how to continue the troubleshooting from here?

[pacmyc]

Also there is a some voltage left on mains cable after it has been disconnected from the mains. Its a few hundred V that quite quickly goes down to under 1 V (within 5-8 seconds), but it was enough to give me a small chock when I accidently touched the end of the cable when i disconnected the TV. Any ideas??

[pacmyc]

I dont seem to get tpp much help / feeback from you guys :s

However, I have noticed that the TV works great in the mornings, but never in the evenings.
I have all the time thought that this was related to the colder temperature in the mordning but
I dont know. I have tried spraying PSU with freeze-spray but no progress.

Could there be any other cause than the surrounding temperature to why the TV works great only in the mornings??

[astracat]

hi
update its software sounds like mercury in lamps taking longer than software time to fire up some models had its start up time increased to compensate for this problem,get from philips consumer support website and put on usb stick
regards
astracat

[downunder]

Try a reflow of pins on transformer 5104 even if they may appear fine.

[pacmyc]

hi
update its software sounds like mercury in lamps taking longer than software time to fire up some models had its start up time increased to compensate for this problem,get from philips consumer support website and put on usb stick
regards
astracat

SW is the most up-to-date.
Version: Q591E-0.103.0.0
Release notes: Release for TV520 R2: Q591E-0.103.0.0
Generation date: 12/05/2011 20:58:01

[pacmyc]

UPDATE:
PSU starts up just fine if I just disconnect the LED panel control from the SSB. (connector 1M20 on picture).
Stable 3.4 V (standby 3V3) and stable 12V. After about 10 seconds PSU shuts down the 12 V but continoes to deliver standby 3.4 V.If I slowly connect the LED panel control while the PSU is still on then the TV will start and everything works! If I turn it off, then I wil have to disconnect the led panel control again to turn it back on.
On the led panel control board I notice that there seems to be a short between pin 2 and 9.

TV behaves the same with and without the keyboard cable connected to the led panel control.

Spare part number of this led panel control is 3104 313 62792 .