Re: Removing SMPS on 22" HP monitor(le2201w)

Just wanted to share my findings.
Using 19VDC laptop brick and a 5VDC from ATX breakout board worked. CCFLs light up and I get an image. Using 12V in place of 19V DC does not work. I do get the 12V at all appropriate places on CCFL inverter(0Z9933 ) but CCFLs do not light up. I get 2 second to black syndrome. However no components are damaged. So it appears that 0Z9933 might not work with 12V or perhaps that peripheral circuitry like the sense pin might not be biased correctly for 12V. Perhaps the zeners or coupling cap that...

Re: Removing SMPS on 22" HP monitor(le2201w)

thank you, that explains a lot. I tried with a 19.5V brick from older DELL Inspiron circa 2006. They are i believe at least 3A at 19.5V. 5V came from a PC supply with one of these breakout boards. [url]http://dangerousprototypes.com/docs/ATX_Breakout_Board[/url]
The grounds from each DC supply were joined together at the chassis of LCD.Re: Removing SMPS on 22" HP monitor(...ve at least 3A

Re: Removing SMPS on 22" HP monitor(le2201w)

So i measured once again and its not a bleed off thing. The node with red wire definitely goes to 19V with respect to ground plane/chassis as soon as AC cord is plugged in. The confusing thing to me is at the same time, I measure 1.2V AC(RMS) with respect to chassis just before the rectifier diode D701 (large pad)? When CCFLS are "on" there is 25V AC RMS there with respect to chassis/GND.
I don't quite understand how this transformer secondary works. How can a 1.2V AC RMS get rectified into 19V DC? I can see how...

Re: Removing SMPS on 22" HP monitor(le2201w)

I took it off of the three transformer ground pin pads see black shaded marking. I also circled part of the ground plane. Ground is shared by both power planes.

Now that i thought about it some I need to verify the following. When transformer is in, and monitor operates off of 120 AC should I be seeing full DC voltage on the plane where red wire is even before the monitor is turned on, i.e AC cord plugged in but enable line low. This is the plane that I am hoping can work with 12V instead of the 17VDC.
I...

Re: Removing SMPS on 22" HP monitor(le2201w)

Yellow wire was connected to 5VDC, the red one to 12V and than I tried with 19VDC.
The monitor worked before the mod and its fine in terms of each individual component. There are no bad components or anything like that, I am just trying to get rid of dependency on 120V AC and run it off of 5V and ideally 12V DC source.

As far as the LED I thought about it. Few years ago I tried the LED conversion with another monitor, but I rushed and ended up cracking the glass....

Hi I am wondering if its possible to replace SMSP on the power board with something that can run off of 12V. I live off of renewable energy and any 120V AC appliance involves using a highly inefficient 12VDC to 120VAC inverter. I would like to bypass this and run the panel off of 12V deep cycle battery and add the 12V/5V buck switcher to power the logic and uC.

Pic of power board is attached.
two threads for LCDs with very similar boards and exact same IC components are
[url]https://www.badcaps.net/forum/showthread.php?t=17348[/url]
[url]https://www.badcaps.net/forum/showthread.php?t=31942[/url]...

Re: New Members - please post your introductions here

New member looking for info on Insignia, likely power supply. I design electronics, I don't deal too much with TVs but have done stuff involving AC.