Build Your Own Arcade Controls Forum

Main => Monitor/Video Forum => Topic started by: lilshawn on March 14, 2011, 01:25:03 pm

Title: neotec NT500 color issues *FIXED*
Post by: lilshawn on March 14, 2011, 01:25:03 pm

getting some streaking...

displaying a white box on a black background results in the left side of the box being white but quickly fades to a yellowy brown color to the right. displaying anything on the yellowy brown portion seems to "reset" the color to normal and begins to change to the right again.

no amount of OSD adjustment seems to fix it.

this board has been re-capped previously by the manufacturer (about a little over a year or so ago.)

the monitor came in for service because there was no display. switching the neck board got the picture back. (there was high voltage, just no pic) the issue with the color has propagated to the replacement board (IE the issue was there before with the original neck board. it has just since died)

i'm going to check the voltages right now, but... any ideas?

EDIT: voltages seem. 140 sits at about 139.6 using a nonstandard crosshatch test pattern (atomiswave). which should read slightly low due to a large white box in the middle) which it does. support voltages are close enough. (15v is 15.1 and 51v is 50.5)

maybe something is wrong with the bias chip? (IC204 - LM2483NA (180V Triple Bias Clamp)) i am having a slight issue when trying to adjust the color temperature... on 9300k and the user settings  it seems gray but changing it to  6500k seems to brighten up the screen. (black is black) even with the RGB gains cranked to 100% in the user setting it seems gray.

Title: Re: neotec NT500 color issues *EDITED*
Post by: lilshawn on March 30, 2011, 01:24:36 pm

Fixed...

After hooking up the monitor to my laptop and running the nokia test program, I was still experiencing the issue. I displayed the color test patterns and noted that the red and green colors displayed absolutely fine. The blue however, did not. It was responsible for "streaking".

While still exhibiting what seemed to be cap failure signs, I scanned through the blue drive section of the neckcard schematic. luckily the simple diagram showed a singe bipolar cap in position C263. (1uf 250v), changed it out and boom! back in business!