Screen is dark and almost unwatchable when watching dark sceens adjusting brightness does not help

Sounds like screen voltage has exceeded much. Its LOT adjustments should be checked. Contact any service technician.
If you wish to get some details; check the site linked here. Pull up older posts. Surf the site with patience. http://electronicshelponline.blogspot.com/

Put the tv it in Standard mode,do the adjustment to the brightness up to +60 shuold be find in the darkness seen.

There are two small holes on the rear side through which you can adjust focus and screen. Use a flash light and locate the two adjustable slots inside the holes. This part carries high voltage. Do not use a metal screwdriver to adjust. Put the TV facing a mirror so you can see how it works. Do not turn more than 1/8th of a turn. The focus control makes picture sharp or fuzzy. Screen control could change brightness. While watching the picture in the mirror, slightly adjust the screen control. Do not turn too much. If it doesn't work, then call a JVC authorized repair center.

Hi Ellie!

Maybe in the manual you can find any information how to resolve this problem.

On this page of the manual there are shown most common receprion problems: http://manualsbrain.com/ru/manuals/979781/?page=72

Hi yes it looks like the inverter has failed and will need replacing, or if your compitent enough you can fix it at board level. The usual suspecs are a small SMD fuse on the inverter board / power supply board and/or buldging capacitors which look like blue or black cans.

hope this helps.
jonno

the problem with LCD tvs are that they have back lamps that shine thru the LCD sceen. the job of the screen is to block the light of the different colors to make the picture. the problem is that the very thin screen can not block all the light. if the set has a back lamp setting turn down the back lamps and adjust the brightness control it should help a little. you my notice that the blacks and dark sceens look better when the room is fully lit and look much worse in a darken room.

Your ballast may not be up to 100% of its rated capabilities, thats often the cause when the brightness level gets to unwatchable levels. You may need to troubleshoot the ballast voltages a defective ballast can usually cause a lamp to loose about 60 % of its brightness levels. The other possibility could be the DLP mirrors need polishing but that is something better left to a repair shop as the DLP mirrors are sensitive

Check the lumans circuit. may be jungle IC

try to open your tv and you can find the flyback ,in flyback you can see the screen and focus to adjust.use and try to rotate the screen,it control the brightness of your unit

could you post make and model?