AVS Forum banner
Status
Not open for further replies.
1 - 4 of 4 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter · #1 ·
I have a 1989 model NEC rear-projection TV, model PJ-4660S.


The picture is extremely green, which is really noticable when the screen should be black [it shows up as dark green]. oh yea, there are green halos around anything bright on the screen.


my first guess was to replace the coolant in the tubes, since i heard cloudy coolant could create halos on the screen. well i replaced the coolant in all three tubes, and the picture only looks slightly better.


next i figured since the red and blue tubes can lose their brightness over a period of time (and these tubes are 14 years old), that i might be able to fix it by simply turning the voltage on the green tube down.


i located the transformer inside the TV that had three knobs on it (for r,g,b level), and turned the middle one down.


now here's the wierd part: it works fine for about three seconds, and the picture looks great... then no matter where the knob ends up, it always goes back to the same color green!


i've been looking at the service manual schematics, and the wire runs off to a page that i didn't get with my manual :p


if anyone has any clue on why my tv is doing this, please let me know here :)


-neil
 

·
Registered
Joined
·
6 Posts
Do you get any retrace on the green CRT? Also you should never have to turn down the screen voltage. Maybe drive in the menu can be adjusted. But if screen voltage is adjusted then you need new tubes.
 

·
Registered
Joined
·
8 Posts
Discussion Starter · #4 ·
>Do you get any retrace on the green CRT?


you mean a visible diagonal line? if so, then no :cool:

>Also you should never have to turn down the screen voltage.


from what i've heard, over time the red and blue tubes lose intensity, but since green is the easiest color to reproduce with phoshphor, it usually stays the same. so after a while, the picture can appear more green. and since you can't turn up the red and blue (they're usually maxed out from the factory), you usually just turn the green down... and for some reason, my green won't go down :( i was thinking it was electronic, but if it's the CRT, i might just throw this thing away and get a decent front projection system :p

>Maybe drive in the menu can be adjusted.


you mean a menu option for crt drive or something? this thing is completely analog, with only a basic picture/tint/brightness menu :(

>But if screen voltage is adjusted then you need new tubes.


:mad: :mad: :mad: :mad:
 
1 - 4 of 4 Posts
Status
Not open for further replies.
Top