Toshiba m35-s456 special edition video problems

hi all i could use some advice on a video problem i am having on a toshiba laptop m35-s456 special edition.

i did an upgrade for some body. his hard drive went out and he wanted a bigger drive and more memory.

i replaced his 80gig hdd with a 160 ide hdd and replaced his 2x512mb pc2700 memory with 2x1gb pc2700 memory.

he also wanted to dual boot with xp and vista. so i partioned his hdd in 3 partions. 1 for vista, 2 for xp pro sp3, 3 for data.

i installed both os in their own partions and loaded all the drivers for alll the devices and came across 1 problem. toshiba does not have a video driver for vista for this model and nvidia does not have drivers for mobile devices.

i did a search and found some info that other people had found a way to get a driver that worked for the this model with success so i tried it.

i downloaded the latesst driver for the ge-force fx 5200 for vista and the fx go5200 for xp and followed the directions to take some lines out of the xp driver and put them in the vista driver so it recognizes the card and it worked fine with full aero glass.

i finished loading all the software and his data from his old hdd and was able to go back and forth to xp and vista with no problems at all. i had the laptop for a few days and testing it on the internet watching dvds and videos with no problems.

i gave the laptop back to the owner and he loved it said it was running faster then ever with no problems.

the next day he calls me and said he has lines on his lcd and could not navigate around to do anything.

i picked up the laptop and asked him what he was doing when he noticed the problem. he said he down loaded nortons 360 and was installing it when he was asked to reboot the lcd had lines all over it.

i got the laptop back and it has thick lines and weird charactors flickering usual signs of video card problems.

i took out the hdd and replaced the memory with original dimms and still have the problem as soon as its powered on before any os is loaded so its not drivers or memory or the hdd. i booted into the bios very hard to see anything and reset to defaults with no change.

i downloaded the lastest bios upgrade from toshiba and made a cd from the the iso and tryed to boot off the cd but i cant see what is displayed and dont know the steps that it takes to do it blind.

i installed another hdd and tried to run the restore with the original cds but again cant see what is displayed and i cant do it blind.

i then tried to do a clean install from a xp cd and that i was able to do blind as i know the steps and booted into xp. i am able to see the desktop in between the thick white and red lines and installed the chipsetr and then video driver but no change so agian confirmed it was from the mobo and it was hardware.

i then took the laptop apart and removed the mobo from it and checked the video card for any signs of burning or over heating and it looked perfect. i removed the cmos battery to reset the bios and put the motherboard back and only connected the power jack, power button, external monitor and booted with the same lines appearing on the external monitor.

i put the laptop together and stll has the lines internal and external.

is their anything else i can do or try without replaceing the mobo and why did the problem appear during norton 360 install.can the north bridge on the chipset cause this problem as it does controll the video or is this 100% from the video card on board.

is their any automatic way to flash the bios or the chipset or it wont do any good.

anyone with any suggestions please help without replacing the mobo as he just spent good money on the upgrade and this would be a good topic for people to learn from.

sorry for the long thread. i wanted to be clear of what was done and when it happened so all the details are their.