Hello, I have Philips 55PFL3907/F7 LCD TV with sound and backlight (I can see the light from behind), but no video. I replaced the TCon board and still nothing. Not sure what to try next. I thought it could be the Inverter boards but the tech at ShopJimmy didn't think so. Any guidance would be greatly appreciated.
-
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Try unplugging ribbon cables from t-con to panel one at a time and see if you get pictureI assume no responsibility for any stupid suggestions I might post. -
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Thanks for replying. I unplugged the one ribbon cable and got a 1/2 white 1/2 black screen. The white side was where I disconnected the cable. Repeated the process with the other cable and go the same thing, with the white side of the screen being on the side of the disconnected cable.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
So happens I have same model with same problem. I have a frc board between the t-con and main board and was getting no data out so I replaced and still have same problem. Unplugging ribbon cables I get same results as you. I know this is not much help. Thinking a main board at this point.I assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Looking at he main board I don't see any bad capacitors, and I tested the fuse. Not sure where to look. I tried finding the SM online but no luck.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Manual: https://www.electronica-pt.com/esque...ileinfo/26605/I assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Thank you.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Would seem like a main board problem. Have you tried input from AV or HDMI. Then possible Eeprom update. Is the tcon getting its voltage. LVDS intact both ends. Just some thoughts.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
maxvaluetech, I hooked up a DVD player and got sound but no picture. I'll have to check the other things when I get home. Thanks for the reply and suggestions.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
From what op is reporting. He's got same problem I have. From my testing I believe I have a good panel, good t-con, good power supply. This tv has a separate frc board. With oscilloscope I get data going into frc but not coming out. Pressing menu button changes waveform. Main ic on frc board gets warm. Checked voltages on frc all seem good. Replaced frc board same problem. I am thinking main board needs to send reset or some signal to frc to enableI assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Does your setup look like this? See attachment.Attached FilesComment
-
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
That's it. Parts seem a little hard to find. You've changed t-con. I've changed the board above the main board. Power board is good. Leaves main boardI assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Main board, correct?Attached FilesComment
-
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Board to right with metal shield over itI assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
This one, correct? I'll start going through the SM and see what I can find on it.Attached FilesComment
-
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Anybody ever verify that the main board was the problem?
I also changed the FRC board because it has working inputs, but no output at all. If it is the fault of the main board, it must be something with the SDA, SCL or, Uart signals. Everything else looks good.
It's hard to accept that the main board is bad when it is doing so many things correctly??
So, anyone ever fix theirs with this precise problem? TIA!Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Op replaced t-con. I have replaced frc. I have not gone further. I think that frc needs an enable signal from mainboard to turn on. My best guessI assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Thanks for responding on this. I believe that you are correct about needing an enable. But, I think it is a complicated handshaking sort of enable.
Almost like the main board forgot that it has an FRC board and is just outputting the data and clock signals that a T-con board would use.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Frc chip gets warm and data going in. Not likely bad frc since two have been changed. So would think mainboard is the problem. Find enable pin on frc and check for signalI assume no responsibility for any stupid suggestions I might post.Comment
-
Re: Philips 55PFL3907/F7 Sound and Backlight, No Video
Hi, i don't have a scope, which signal do you measure? differential one? what type of wave do you see and with which frequency range? How do you think that a bad comm signal main<>frc can result to lvds data sent? power supply tensions generated on frc how do you have checked, with the help of schematic? I have repaired an frc board (Philips), there is a switch transistor to feed power to the panel, it was broken togheter with a linear regulator, are you sure you have 12v on the tcon? Thinking of the flat cable test it seems to be good, but in this case is serial comm between frc<>tcon that don't work (but this can still belong to mainboard). I think that a SM reset, and eventually a SW reflash+SM reset is a next step. BYELast edited by Davi.p; 10-18-2017, 01:59 PM.Comment
-
Hi all,
Ok so I have this beautiful un55h8000 samsung tv with sound but no video nor backlight. When turning the set on the red light blinks 5 times.
The screen shows no damage and backlight turns on when I disconnect the power supply from the main board. The tcon board only has 2 out of 3 leds on.
I came across this page and followed the different steps: https://techhometravel.com/samsung-u...ight-no-video/
- Unplugging the main board cable at the power supply >>> backlights came on.
- BLU_ON signal from the
- Unplugging the main board cable at the power supply >>> backlights came on.
-
this tv is throwing me for a loop. do samsung tvs no longer have the backlight self test feature built into the power supply?
i tested the backlight with my LED tester and it lights up both strips. one of them reads 100v and the other reads 63.7v.
unplugged mainboard from power supply but left backlight plugged in, and then plugged psu wall power in. expected to see backlights light up but see nothing.
according to how ive diagnosed in the past, this would almost always be a bad power supply. replacement power supply was cheap like 20$ from ebay. but still i get not even... -
Hello everyone,
Ive got a UE60KU6079 on the workbench that is giving me some headaches trying to troubleshoot.
The previous owner stated that there had been white dots on the screen which from the description sounded like some lenses fell of the backlight LEDs.
He had opened the TV from the back, trying to get to the backlight, supposedly gave up, reassebled everything and gave the TV to me.
I expected the worst like ripped COF cables or a cracked panel but could not find anything like that yet.
Anyway I still fully expect that there has been something seriously damaged... -
when i power on the TV is black ,Do I remove the right or the left ribbon I get respectively the right or the left half screen working
Do I disconnect the plug from the power supply, no backlight
Thought the backlight would light up when you remove the plug from the power supply but no
What could be wrong if both halves work separately?... -
I am working on a Samsung un55cu7000d which has backlights and audio. There is no picture. This model does NOT have a separate TCON board. Before I order a main board I would like to try and confirm that the issue is not in the display. The ribbon cable from the main board goes directly to the display and I can then disconnect the left from the right. When I disconnect the right side the display lights up on one side but has no video being displayed. Can you all give me some guidance on how to confirm the main board is the issue.
Comment