Let’s first make the RS 232 to TTL Converter Cable/Jig or ECS as referred to later on in the tutorial.. Without this you would not be able to use the software!! So either make the jig of get a jig from someplace like ebay.

One link to it is : Ebay only $16-$20.
I however, used the following items to construct my $0 Converter as I got the parts from the engineering lab of my college which I will return soon.
1. MAX233CPP or MAX233A Chip. DataSheet for Max233.
2. BreadBoard and those tiny cables to hook up on it.
3 A Ribbon cable (so I could strip it into individual cables, you can use cables available as long as they are not too thick, as they will need to be interfaced to Db9 Female connector). Total individual cables needed were 4 + 6 = 10.
4. DB9 Female Connector
5. 1 Female Pin Header Connector (those cable ends you see on your DVD/CD roms, audio connectors).
6. Soldering Iron to solder the wires to DB9.
7. Computer with Serial port, preferably COM1 not the LPT port (the printer port, the big one is usually the printer port)

Use the diagram shown below Fig (RS) to make the wire connections on the breadboard or making hardwired system. MAX233A or MAX233CPP are basically same stuff. And has advantage over MAX232 method to make the RS232 to TTL converter that it does not need any external Capacitors. Please note the MCU happens to the monitor control unit or the TTL itself. And keep TX and RX such that you can swap each others location as I had issue communicating till I placed RX on Pin 2 and TX on Pin 3 of MAX233CPP. These RX and TX are your monitor Transmit and Receive signals. On DB9, make the connections as shown basically Pin 2 > Pin 4 of MAX233 , Pin 3 > Pin 5 of MAX233 and Pin 5 > Pin 9 of MAX233 (GND). And short the Pins 4, 6, and 8 on DB9. And you are done with interfacing the RS232 to the chip (Max233).
Now on your monitor backpanel, some monitors might need the casing to be removed but I was lucky Dell P1110 has a small cover on the interface which you can pull out. Basically the format for monitor is :
Top to bottom as you face the back of the monitor applies to (Dell P1110)
GND
VCC (+5)
TXD
RXD .
You will need the 4 pin female header pin connector (5th item in my list) to easily interface the Monitor with Chip (MAX233). You might need to switch around between the TX and RX for monitor to Pin3 and Pin 2 respectively on MAX233, if the diagram below gives you errors on Windas like “Program termination” or “check bus lines”. I turned my monitor off before doing the interface to prevent any shock hazard to myself.

Fig (RS): Rs232 to TTL converter cable/jig interfacing using MAX233.

Now your converter cable/jig is ready. Let’s now install the software and steps to change settings for monitor. These steps have been taken from http://www.geocities.com/gregua/windas/ . Gregua is the original owner/writer of the entire tutorial for fixing the brightness issue. Thanks mate.

Stage 2 : Hacking your monitor or changing its configuration using Windas

Download this zip file . Open and extract. You should see the contents as figure below.

Execute the windas.exe file, and bypass the errors you see, like AG Astro not configured etc. etc. if any. When the program has fully executed, you will see the screen like this :

Go the Setup option and click Model Set , if you see screen as below you do not need to play with activex folder. If nothing opens just go to activex folder in your windas folder and execute the activex.bat file. It copies the required file and registers the controls. Now try windas and model set, you should see the screen as below, if not, I would suggest you try to get in touch with the dude who wrote the procedure at http://www.geocities.com/gregua/windas/install.html . Please note that the procedure written here on this blog has been modified here to ease the installation of windas, with all the steps properly executed and the folder and zip created as seen on geocities.

Now run ‘Set up’->Config and you should see the following.

Congratulations! You have successfully installed and patched Windas!
With your Rs232 to TTL cable (or ECS as referred to in how to change settings for your monitor using windas guide) windas will be fully functional! Make sure to back
up your current monitor config before doing anything else. Please note here that it might blank you monitor for a few minutes while saving when you hit the GO button. Its normal do not worry and do not try to cycle power to the monitor.

Final Stage : Editing and Uploading .dat Files Saved from Monitor and changing G2 value which is responsible for excessive brightness.

These steps are copied and taken from original soure : http://www.geocities.com/gregua/windas/adjustment.html

1.You may want to configure your Ecs com port (the interface Rs232 to TTL converter cable/jig) and set SG to manual

1. Before doing anything save your current settings as shown.
   
   
   Note:Your monitor may seem to turn off (blank) during saving and loading of register data. This is normal.
2. Windas has a utility to interpret saved .dat files under help->expert
   
   
   You want to click ‘Viewer’ > And locate the G2 Value and remember it as it might be hard to find it in the .dat file.
   
   These are the values of the settings of your monitor saved in the .dat file
   You can change ANY of them, as will be shown in the next step
3. Open up your .dat file with note pad, turn wordwrap on and adjust the size of the notepad window
   Note for WindowsXP users: WindowsXP (and likely Vista) notepad
   no longer saves entirely in ASCII chars and will encode the content
   differently when you save. Use a hexeditor, or another editor such as
   Vim (www.vim.org). Or, you can use the edit command on the command prompt. Also you can just try wordpad as i did, and use wordrap from View>Options>Text > Warp to ruler or Wrap to window whichever works for you. Locate the G2 number say in above example its 84. Locate it and change it gradually to lower value say 80 or 78 and save the .dat file. Say here it is dang.dat.
   
   As you can see above, the viewers output is simply your dat file with labels.
4. Can you find the G2 voltage adjustment? Perhaps you want to lower it.
   Bring it down about 4, then save your .dat file, make gradual adjustments.
   
5. With your dat file edited and saved, load your changes back into the
   monitor as shown. Please note use the Expert>Viewer to check for the files changed G2 value, if it has not changed means you did something wrong, go back and edit the value and make sure using viewer first that value got saved. Now after you hit the GO button while loading your monitor might go blank(no power etc.) do not worry after programming is done it will come back on. If after like hours i does not, try recycling the power to monitor and if still blank seems like monitor is toasted. Something went wrong somewhere, but i doubt that will ever happen.
   
   Just click go, then hit ok when it is finished loading.Otherwise your OSD will remain locked.
   

Now you are all set , play around with the OSD settings and repeat above procedure to load new values of G2 till you are satisfied with the brightness level.Enjoy and big thanks goes to gregua for the entire guide and software files etc etc. and other user from icrontic.com who provided various tips and methods.