I have a toshiba laptop about three years old Wont start up right

Either the power supply is not working or the battery has failed and will not hold a charge. If the laptop is 3 or more years old, the battery is the likely suspect.

you need a balist.

olso in the cust menu is a quick start mode . turn it off

This is the monitor not being attached to the Graphics Card properly.

in the cmos setting load default and save it. restart the computer

I have the solution for the non booting Toshiba that I wrote almost a year ago. This tutorial (written and pics from the repair of my m35) is applicable to laptops that shut down without any warning, laptops that turn on only sometimes, and laptops that simply refuse to turn on (LEDs blink, fan spins up for a second and then everything just goes dead). So if your laptop does not turn on, it goes completely dead within a few minutes after bootup, here's the link to the tutorial. The repair takes about an hour, there's no need of replacing any parts, reinstalling any software or any other thing. The only investment in repairing your laptop with this tutorial is your time. Basically, you can repair your laptop within the hour, without spending any money for any parts or software.
http://imateski.blogspot.com/2008/08/toshiba-satellite-m35x-motherboard.html

It would be oen of three things... in order of cost;

1. LCD Invertor has gone bad
2. SCREEN has gone bad
3. Motherboard has gone bad

In either of the three it would most likely take a toshiba tech to pinpoint exactly the problem and do the repair. Although if you are handy enough you can get the parts and repair it yourself.

Ebay - new screens $110-$135. Google for step-by-step replacement instructions.

Try cleaning the RAM.

If you're working on the computer when that happens, it's not probably a power setting. Try to update your BIOS to the most current version at the toshiba support website (support.toshiba.com) & see what happens. Fixes the issue most of the time

I hope this helps.

I have the same problem. My detetor is three weeks old. I am sending mine back under warranty to the merchant or Cobra directly.