Hi, I have a DTS42W Electrograph that turns on but no image coming on but i can see the on screen menu perfectly, help please!!!

esupport.sony.com

00271,00279,00277. Try these codes. If you wish to get more, check the sites linked here. It has setup codes, and setup procedure to many popular brand remote controls. Pull up older posts.
http://electrohelponline.blogspot.com/
http://electro-medical.blogspot.com/

that i cant help, but there some other blocks who can help.keep looking.

Sounds like The main power supply regulator section circuit fault. Either it will be a separate board, or the part of main board. Check and replace damaged component/s at its main power regulator [SMPS] section circuit. Contact any service technician. If you wish to get some details; check the site linked here. Pull up older posts.
http://electronicshelponline.blogspot.com/
It will be best to replace the power supply regulator board as card basis rather than making "Surgery" to it; which usually will make loss for both money and time. Even though you can make it right, it will cost around an amount equal to the cost of a new board; including the cost of (spare parts + service charge) More to say, most of the spare parts to it will be difficult to get from open electronic spare part market. This is true to most of the flat panel TV power supply boards; irrespective of its brand and screen size.
Search the site by type in the "brand name" to your device; [Exclude the model number], in the "Search box at the top right of the display window of the Homepage" to get gathered related posts.

I have a 42" Electrograph plasma and it has a 2" black vertical line on the left side of the screen.

what kine of additional plug i need to plug in i am having problem learn how to trouble shooting the power in the tv also i am having problem with the tv tube i am trying to learn how to do these thing so that can help myself and my letter son i have no money ta this time is there anyway that you all can help me thank you

Try resetting the ee-prom in sub menu

this might be too late, but i have this board and am looking to sell it.  Let me know if you are interested

It's Y upper buffer, also cross matches, with LJ41-02760A which is for Samsung 42 Plasma

Replace Q8023 (top224y) which you will find is blown apart or it's shorted, and the Q1 (2sk2662) which would check to be shorted inside the heat shrinked wrapped board next to the blue relay and the smd zener diode ZD8018 (shorted) along with the ceramic fuse F8001.
I don't remember the value for the zener diode but there's lots of them with the same color code. You will have to take one of the others off to test on a resistor jig to get it's value.
The 2SK2662 is a cross for the original.