Viewsonic VA1912W

[djrock]

Hi, After recapping my LCD and getting it working (All caps on the power/inverter board except the mains cap). I can't seem to get rid of the backlight flicker. The pictures fine so it must be the backlight. When its cold it flickers slightly and then eventually disappears. Looks like its more at the top half of the screen. After it has stopped if I turn it off then on, it flickers but not so noticeable.

Any idea's how to fix it?

Thankyou

djrock

[PlainBill]

Re: Viewsonic VA1912W

Hi, After recapping my LCD and getting it working (All caps on the power/inverter board except the mains cap). I can't seem to get rid of the backlight flicker. The pictures fine so it must be the backlight. When its cold it flickers slightly and then eventually disappears. Looks like its more at the top half of the screen. After it has stopped if I turn it off then on, it flickers but not so noticeable.

Any idea's how to fix it?

Thankyou

djrock

There are several possibilities.

1. Did you replace the small (< 100uF) electrolytics on the power supply? I had problems with one supply that would become erratic at full load; the problem was traced to the 22uF startup cap.

2. What brand and series caps did you use?

3. At end of life, CCFLs have a tendency to flicker, turn pink, or exhibit other problems.

PlainBill

[djrock]

Re: Viewsonic VA1912W

Hi PlainBill,

1. All the electrolytics caps (except mains cap) were replaced. Unless ones hiding away.
2. They were replaced with Ruby ZL's.
3. Never thought about that. Of course. Just like what happens to the version used to light a room when they get old.

Here's a picture of the board pre recap


Thankyou

[teosat]

Re: Viewsonic VA1912W

hello all.i have the same monitor model va 1912w i wanna ask are the mosfet ic's both same? in my power supply are two of them one with P605/BD622T an the other p605/bd6242.ty for all answers.

[pubudu.panboo]

Re: Viewsonic VA1912W

All the electrolytics caps (with mains cap) were replaced. but my lcd monitor same as before.only lights power light and off after 2 second display not coming..

[Rtech]

Re: Viewsonic VA1912W

In nearly all cases with this board,with this fault , it is usually the AP605 mosfets that fail.

[dj_ricoh]

Re: Viewsonic VA1912W

try to put a flash light on the display.
you may got a bad lamp so you need to replace the lamp
http://www.youtube.com/watch?v=eORAoaWpqao

[pubudu.panboo]

Re: Viewsonic VA1912W

all so change the 40to3gp transistor and pico fuse...also pico fuse brunt when i power on...

[budm]

Re: Viewsonic VA1912W

You need to check those four 8-pin MOSFETs by the inverter transformers as RTECH has suggested.

[roamingraman]

Re: Viewsonic VA1912W

can someone help me to solve this? viewsonic 1912w., seems all the secondary voltages are okay. I am getting the green led on. no backlight. no display. No changes found when power button is pressed(green led remains on)

[budm]

Re: Viewsonic VA1912W

https://www.badcaps.net/forum/showthread.php?t=39740