Acer Monitor X233H b.

[T Marshall]

Hi
Can anyone help with schematics of power board for above Monitor.
I have got schematics for X233H but this X233H b is completely different.
Uses a TL494 IC.

The problem is,the two fluorescents only briefly light twice.

Many thanks

 

On Wed, 14 Apr 2010 11:25:23 +0100, T Marshall
<tommy-krihc@tiscali.co.uk>wrote:

Hi
Can anyone help with schematics of power board for above Monitor.
I have got schematics for X233H but this X233H b is completely different.
Uses a TL494 IC.

The problem is,the two fluorescents only briefly light twice.

Many thanks

I would be looking more at the inverter or maybe one of the
fluorescent's being bad than the PSU unless you've verified
the PSU is bonked somehow.

 

[T Marshall]

Meat Plow wrote:

On Wed, 14 Apr 2010 11:25:23 +0100, T Marshall
tommy-krihc@tiscali.co.uk>wrote:

Hi
Can anyone help with schematics of power board for above Monitor.
I have got schematics for X233H but this X233H b is completely different.
Uses a TL494 IC.

The problem is,the two fluorescents only briefly light twice.

Many thanks

I would be looking more at the inverter or maybe one of the
fluorescent's being bad than the PSU unless you've verified
the PSU is bonked somehow.
thanks for reply. Its the inverter and control section I am trying to

check. Every thing else seems to be ok. It did fire up once and display
picture OK. looking for circuit to see if I can inhibit error detection
Tommy

 

On Wed, 14 Apr 2010 14:57:36 +0100, T Marshall
<tommy-krihc@tiscali.co.uk>wrote:

Meat Plow wrote:
On Wed, 14 Apr 2010 11:25:23 +0100, T Marshall
tommy-krihc@tiscali.co.uk>wrote:

Hi
Can anyone help with schematics of power board for above Monitor.
I have got schematics for X233H but this X233H b is completely different.
Uses a TL494 IC.

The problem is,the two fluorescents only briefly light twice.

Many thanks

I would be looking more at the inverter or maybe one of the
fluorescent's being bad than the PSU unless you've verified
the PSU is bonked somehow.
thanks for reply. Its the inverter and control section I am trying to
check. Every thing else seems to be ok. It did fire up once and display
picture OK. looking for circuit to see if I can inhibit error detection
Tommy

If you are looking for an inverter circuit using the 494 here is a
simple circuit that may be some help.

:http://www.eleccircuit.com/wp-content/uploads/2007/08/inv4wcct.gif

Note the feedback loop.

 

[who where]

On Wed, 14 Apr 2010 14:57:36 +0100, T Marshall
<tommy-krihc@tiscali.co.uk> wrote:

Meat Plow wrote:
On Wed, 14 Apr 2010 11:25:23 +0100, T Marshall
tommy-krihc@tiscali.co.uk>wrote:

Hi
Can anyone help with schematics of power board for above Monitor.
I have got schematics for X233H but this X233H b is completely different.
Uses a TL494 IC.

The problem is,the two fluorescents only briefly light twice.

Many thanks

I would be looking more at the inverter or maybe one of the
fluorescent's being bad than the PSU unless you've verified
the PSU is bonked somehow.
thanks for reply. Its the inverter and control section I am trying to
check. Every thing else seems to be ok. It did fire up once and display
picture OK. looking for circuit to see if I can inhibit error detection

The main switcher and the inverter monitoring are totally separate on
every LCD monitor I have worked on. The backlights are fired at full
brightness, then the current feedback circuit kicks in to achieve the
preset level. If the monitoring chip detects an imbalance between the
2 (3) tube drivers it shuts them down.

Best suggestion: get onto badcaps.net and usually someone there will
steer you through this. Circuits are rarely required.