Hi everybod. I've got that kit now JV LT-49CF890. It is been a working and just black screen while they were watching tv. So, it looks the backlight is working as i can see it working when switch the tv on, i can hear and the sound from the menu. I think it is already in factory settings. Any suggestions before to proceed with disassembling guys? Some tricks or ideas what to look for when remove the back cover? Thanks.
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Re: JVC 49cf890 - Fire TV - no picture but sound
Tadaaaa... no T-CON board or not in the way i expected to see
Nothing changed if i disconnect the ribbon cable from the main board. Nothing changed if i tap on the ribbon cables connected to the display. So, shall i buy new main board or maybe the fault is in the board attached to the screen? -
Re: JVC 49cf890 - Fire TV - no picture but sound
on the power supply is ther a pin that says bl-on or somethink like that as thats the back light on voltage what voltage is on that pin when tv fisrt switched on and when just a black screen.
there is a repair kit for these boards with no backlight issue these are the parts too check
Q17
U9
D27
R78Last edited by vinceroger69; 11-19-2021, 05:26 AM.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
Backlight is working. I can see it when i switch the tv on.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
No, i have not checked the led strips as i thought it will be something about the boards if the backlight is working.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
just read this post a lot of people are having issues with this tv model a lot of it seems firmware related too.
https://uk.amazonforum.com/s/questio...ith-everythingComment
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Re: JVC 49cf890 - Fire TV - no picture but sound
Yeah, acording to this post this TV is piece of sh.t
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Re: JVC 49cf890 - Fire TV - no picture but sound
Need to check if you have power on your t-con. Fuse good. Check for various voltages at test points.I assume no responsibility for any stupid suggestions I might post.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
post 2 picture 3 under the ribbon cable connector there is a fuse marked N what votage do you get on each side of that one meter lead on metal tv chassis then test voltage each side.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
Briefly or ? You can see BL seeping through holes in the metal panel base, if you open the back of the TV.
Do you have Video ? if the Screen is black : press Menu button, so you know you (should) have an image, and use Flashlight on the screen to detect the faint image.
No Backlight : it works briefly and shuts down : Most likely dead LED is disconnecting the circuit : Buy new set ( using the Model printed on the Strips) , or , if you have same hue and brightness LED - Replace.
No Video : This is Main - Tcon - Panel line. Involves electronics Troubleshooting usually. Clean the LVDS connectors. Check that Main receives Power ( as printed on the PCB, near PSU-Main connector) by checking pins or detecting onboard. Check the T-con Fuse , Check Panel long boards .
According to results you can decide on electronics or new board path.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
My money is on a bad T-con. But there's a reason I don't bet.I assume no responsibility for any stupid suggestions I might post.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
Still a t-con. True there not just board swaps, but can be repaired.I assume no responsibility for any stupid suggestions I might post.Comment
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Re: JVC 49cf890 - Fire TV - no picture but sound
I believe the t-con is on panel strips.I assume no responsibility for any stupid suggestions I might post.Comment
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Hi, I have a Samsung UE50TU with:
- sound and backlight, but no picture
- when it arrived, it had a picture for a few seconds
- it keeps rebooting
- without ribbon cable between the two panel boards, it does not reboot but I have no picture
- without cable between mainboard and lcd panel, it does not reboot (but obviously i have no picture)
- when i try a tape fix, its keeps rebooting, unless I tape off pin 1 (the innermost pin). In that case it does not reboot but I have no picture.
- without cable between mainboard and lcd panel and with a jumpered... -
I have a 60 inch Samsung UN60EH6000F flatscreen TV. The screen went black a few months ago Sound is good, backlight is good, no menu. I replaced the TCon board with a used board purchased from Ebay. It worked fine for a 3-4 months, then the screen started ‘fading' back. Once again, sound is good, backlight is good, no menu. However, this time the picture looks fine for about 10-15 minutes, then fades back. If I power cycle the TV, the display reappears, for another 10-15 minutes, then fades black again. Repeatable ever time.
I ordered a supposedly ‘new' Tcon board this time, and... -
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... -
Hi all
I was just given a Samsung TV with the issue. I read various threads and videos and attempted the ribbon tape method to gain an image, but no luck.
Symptom:
No picture no sound.
When I plug in the power cord, Backlight LED turns on for a half second and then turns off. The red LED next to the power button located center bottom flashes 2 or 3 times. When the power button is pressed after, it does the same thing.
No sound at all.
What I tried:
1. I tried unplugging the left or right ribbon... -
so i took out one of my spare gigabyte ep35-ds3r mobos from storage for use to do some cpu, ram and video card testing of stuff i bought from ebay and got for free from momaka. he bought 50 e8400 cpus for cheap from ebay some years ago and i decided to help him relieve him of some of his supply since he had waaaay too many!!
what did we say about hoarding too much stuff and depriving others of them?! *cough* socialism *cough* lol! 
i had to blow some dust off the board and heatsinks with the datavac as i didnt clean it up before putting it in storage. after finishing...
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