Screen went blank

I also have an old computer with SATA hard drive running XP SP2, it is connected to samsung LCD tv, it was working properly for months but today while i was using it, the screen went blank(black) nothing showing on lcd, I tried every thing i can but of no use, even connected to other monior also but... nothing displaying, Cpu is running but when I tried to turn it off from power button it didnt response, have to switch it off from electric board......

Yesterday I downloaded and stalled SP 3.5 from Microsoft official download site is it the reason...... what should i do

Please halp.

sounds like the mobo is fried.

do you have a spare graphics card?

if you do plug that in to see if honorgamers suggestion is correct. maybe it is just the video??

Yaa m using a VGA cable,

Dont have a spare Graphic card...

Installing SP 3.5 is not the reason right ?????

Thanks for your concern and help.... Yaa I tried another Vga cable but still not working (first VGA cable working fine when i connected my laptop to tv)