Just what does a LCD Inverter do?

[Bill Z]

I’m in the market to get a new LCD for a T30 because the one I have is really cracked (several cracks going in many directions).

I see here on this forum that it is advised to get an inverter with the LCD if you are changing LDC FRUs. Just what does the Inverter do? Where in the T30 laptop is the video card? Is the video card part of the inverter?

If I go from a 1024X768 LCD to a 1400X1050 LCD but the new LCD has the same brightness lumens, can’t I use the same (older) inverter especially if the manufacture makes both LCDs?

Please help.

[AlphaKilo470]

The inverter provides power to the backlight.

[pianowizard]

But what does it "invert"?

[Harryc]

But what does it "invert"?

Traditionally an inverter converts DC to AC. In the case of an LCD inverter, it is involved in controlling the power/dimming circuitry to the backlight.

[Bill Z]

But what does it "invert"?

Traditionally an inverter converts DC to AC. In the case of an LCD inverter, it is involved in controlling the power/dimming circuitry to the backlight.

So, if a LCD is listed as having 150nit, why wouldn't any inverter providing 150nit that physically work?

[pianowizard]

Traditionally an inverter converts DC to AC. In the case of an LCD inverter, it is involved in controlling the power/dimming circuitry to the backlight.

So, I guess "controller" or "converter" would be more appropriate.

[Bill Z]

Traditionally an inverter converts DC to AC. In the case of an LCD inverter, it is involved in controlling the power/dimming circuitry to the backlight.

So, I guess "controller" or "converter" would be more appropriate.

Guys, Its not so much what you call it, just what does it do for you.

Can these things be swapped around some but keeping the nit count the same.

I'm trying to learn something here.

[Harryc]

I am no expert, but here's the best answer I can give based on what I've learned. You can't swap inverters between families of Thinkpads because the physical connections, size, and function of them are different. You can use them within the same family with some exceptions. For example I can use a T41 XGA inverter in a T42 XGA machine, but I would need an entirely new inverter (and LCD cable) to support a UXGA flexview upgrade in the same model. So, I think the answer to your question is that it depends on what you are replacing, and in which machine. Someone would have to research your T30 question, I don't have time at the moment. Here's where the research would start -
http://www-307.ibm.com/pc/support/site. ... 42348.html

[Reo51St]

An inverter converts DC to AC. The AC voltage starts the backlight and then maintains the required voltage to the backlight.

http://www.designnews.com/article/CA473494.html

[Davemci]

Exactly right, and a converter converts a DC voltage to a different DC voltage.

An inverter converts DC to AC. The AC voltage starts the backlight and then maintains the required voltage to the backlight.

http://www.designnews.com/article/CA473494.html

[joester]

In the case of the CCFL's (cold cathode flourescent tubes) used in laptops, the inverter does indeed change the DC voltage to around 2000 VAC. Not only that, but at a frequency so high it will burn you before you realize it. Careful messing with them. You'll get burnt, not shocked.

Joe

[rkawakami]

See my post from last December about my attempt at measuring the output voltage from an inverter.