Re: Philips 49PUT4900/12 no backlight
The voltage was measured both with and without the LEDs connected and in both cases it was fluctuating.
I will take out the LEDs later today and check the individually
Repair_dane
Member
Last Activity: 06-10-2023, 04:37 AM
Joined: 05-04-2020
Location: Fyn
-
Philips 49PUT4900/12 no backlight
Hi guys,
tv turns on and works as usual, but without any backlights.
LED-tester shows that the LEDs seem to work fine (54V and 25V supply)
However the LED voltage on the board is fluctuating between 0 and 50 (can not make precise reading. Happens withing a second)
Capacitors look fine
Any ideas?... -
How to open Beovision V1-40?
Hi guys,
I have a Bang & Olufsen Beovision V1-40 on the repair table at the moment. It is broken, but I can't even figure out how to open the tv without damagin the case. All screws are removed. Anyone knows this one? -
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 sinceLeave a comment:
-
Re: No backlight but LEDs are fine
If you can't find the error there is always the possibility to install a CA-288 board and run the LEDs that wayLeave a comment:
-
Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times
Thank you for the advice. Though I doubt it is that easy I will give it a try...Leave a comment:
-
Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times
Yes...Leave a comment:
-
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...Leave a comment:
-
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 wentLeave a comment:
-
Re: Philips 65PUS7803/12 is only turning on video 1 out 5 times
Nice try. Warranty over. Reciept gone missing anywayLeave a comment:
-
Philips 65PUS7803/12 is only turning on video 1 out 5 times
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... -
Re: LG 42LE4500 PSU Replaced Backlight Failing Again
True. But covid-19 is definately causing some delays...Leave a comment:
-
Re: LG 42LE4500 PSU Replaced Backlight Failing Again
If you don't have an LED tester, you can try and connect some 9 volt batteries in series. Assume every LED needs 3V. Sum up the numbers and connect the amount of batteries you need. Then use it as a tester, but be careful, since you are building up some voltage even though it is only batteries...Leave a comment:
-
Re: LG 42LE4500 PSU Replaced Backlight Failing Again
You should be prepared for a long wait if you do this.
I ordered new LEDS 26.04.2020 on aliexpress and paid extra for faster shipping So I would get them after 14-23 days. I am still waiting for them to arrive...Leave a comment:
-
Re: Samsung UE55F7005STXX - 5 blinks, screen dark
That's just my writing. The value was 12,52V. I'll do some more measuring this weekend.
I see that a new T-con would cost me about 20$ so it's worth a try....Leave a comment:
-
Re: Samsung UE55F7005STXX - 5 blinks, screen dark
Just for the heck of it.
Power board measurements
Everythink ok...Leave a comment:
-
Re: Samsung UE55F7005STXX - 5 blinks, screen dark
I'll just try those pictures one more time...Last edited by Repair_dane; 05-28-2020, 02:29 AM.Leave a comment:
-
Re: Samsung UE55F7005STXX - 5 blinks, screen dark
So I've been through the bunch and attached the measurements
TCON_READY is 0,00V, which I find a bit suspecious. Maybe I'm lucky and it is just a dead T-con.
I still can't emergency start the tv no matter what I unplug or reset. The internet doesn't seem to know of any "safe boot" for Samsung tv's
The chip under the heat sink gets hot as well, even if the tv is never really booting up. the plate is maybe a little warmer than body temperature...Leave a comment:
-
Re: Samsung UE55F7005STXX - 5 blinks, screen dark
Took me a moment to locate it, but you are indeed correct.
There is a third LED, which is not coming on.
The LED's which are on drag 2,65 volts whereas the third only got 1,18.
I can't find any schematics for this exact model, so I'm not sure about the voltages around should be.
I get 12,5 after the fuse on t-con
and and 3,3 acround some of the mlcc caps close to the led, which sounds reasonable...Leave a comment:
-
Re: Samsung UE55F7005STXX - 5 blinks, screen dark
Budwich, are you aware of any damage this might have caused?...Leave a comment:
No activity results to display
Leave a comment: