Philips 65PUS7803/12 is only turning on video 1 out 5 times

[Repair_dane]

For a month now my Philips 65PUS7803/12 has had problems on startup.
It boots up every time, but 4/5 times it has no video. Sound and LEDS are on.
You can shut it down and try a couple of times again and eventually it will come on after 4-5 times.
It stays on and for the next hour or so it is possible to turn on the tv at once first try.
It also has a pretty high standby voltage for an hour or so after shutting down (14 Watts +/-). After an hour it will drop to a more decent 0,1W

I am pretty sure it is a main board fail since everything else is endeed working, but I might be wrong.
What do you guys think?

I want to avoid opening the tv if I can. these 65" screen are too big for me to handle without cracking the panel and if it is the mainboard I can't repait it anyway

[William1967]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

The TV is from 2018, is the 2 year warranty over? If not contact the shop where you bought it.

[Repair_dane]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

Nice try. Warranty over. Reciept gone missing anyway

[dick_barton]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

Philips documentation for your set says

• Standby power consumption: <0.3W

so if you have 14W for an hour or so I guess it's not going fully into standby and is a possible power supply issue. No real way of knowing for certain without the back coming off and doing some measurements.

[Repair_dane]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

Thank you for this answer.

Power supply I can work with. There some screws in the bottom of the back cover. I hope it is possible to open it this waay. I'll try this weekend and give an update how it went

[Repair_dane]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

It seems that the issue was the t-con.
I get 12V on the tcon fuse, but it stops after the first transistor.
I have no voltage on cofs when screen isn't working, but voltage when it does.
Can anyone help with ordering a spare transistor? I can't figure out how to identify it

It says 34P F7

[dick_barton]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

12V on both sides of the fuse?

[Diah]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

It seems that the issue was the t-con.
I get 12V on the tcon fuse, but it stops after the first transistor.
I have no voltage on cofs when screen isn't working, but voltage when it does.
Can anyone help with ordering a spare transistor? I can't figure out how to identify it

It says 34P F7

dont play with yours t-con-

just downgrade the firmware.. here you are

under nur 2018 download only with upgrade_loader files with .pkg format

[Repair_dane]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

12V on both sides of the fuse?

Yes

[Repair_dane]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

dont play with yours t-con-

just downgrade the firmware.. here you are

under nur 2018 download only with upgrade_loader files with .pkg format

Thank you for the advice. Though I doubt it is that easy I will give it a try

[Repair_dane]

Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times

Update: problem solved
Updating the firmware did not help
I ordered a new t-con from aliexpress and installed it. TV came on immediately and has been working ever since