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.
Thank you to the guys at HEGE supporting Badcaps [ HEGE ] [ HEGE DEX Chart ]
Announcement
Collapse
No announcement yet.
JVC 49cf890 - Fire TV - no picture but sound
Collapse
X
-
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
-
Re: JVC 49cf890 - Fire TV - no picture but sound
Originally posted by Dobsuk View PostNo, i have not checked the led strips as i thought it will be something about the boards if the backlight is working.
Comment
-
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-everything
Comment
-
Re: JVC 49cf890 - Fire TV - no picture but sound
Originally posted by Dobsuk View PostBacklight is working. I can see it when i switch the tv on.
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
-
Re: JVC 49cf890 - Fire TV - no picture but sound
Originally posted by vinceroger69 View Postpost 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
-
Re: JVC 49cf890 - Fire TV - no picture but sound
Originally posted by Ancient1 View PostBriefly or ? You can see BL seeping through holes in the metal panel base, if you open the back of the TV.
Originally posted by Ancient1 View PostDo 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.
Comment
-
Re: JVC 49cf890 - Fire TV - no picture but sound
Originally posted by Dobsuk View PostThanks, will check this later. Anyway i ordered new main board as they were about 16GBP But will check and that fuse.
Comment
-
Re: JVC 49cf890 - Fire TV - no picture but sound
Originally posted by dskall View PostStill a t-con. True there not just board swaps, but can be repaired.
Comment
Comment