Laptop suddenly shut down help!

my laptop cheap schuddenly shutting down witout a reason i instaled win 7 again.

it shut down with the instal doesnt matter.

motherboard deaD?

Toshiba Satellite A200 (PSAE6)

PSAE6E-06U030DU, Laptop,
Intel Core 2 Duo T5250,2 GB,15.4 inch,

1280x800,ATI Mobility Radeon HD 2600,160 GB, 

win 7

motherboard iskaa LA-3481P intel chipset 965GM

CPU might be overheating

i putt new termal compound on it its about 50 till 70 degrees 

any idea somebody?

Battery might be going bad. Parts over heating. Try getting cpuz and/or core temp and see what the average temps on idle and before it shuts down is. Therm compound may be dried up so you might have to reply new one. 

battery can be its on the power i replayed thermal compound on videochip cpu bridge chip shutting down temp core 1.0 higest 70 degree. ?

Can you repeat that please...? I sorta can't understand it. 

battery out the laptop its on power.

replayed termal compound to cpu gpu chipset.

used temp core 1.0.

highest degree 70+

Your cpu heat seems a bit high for a laptop. 

the cpu olso works alot 20% most of the time

If you are playing a lot inside the machine, then I would check that the fan is connected. Seen many forget about the fan or that it somehow disconnected itself.

yeah fan is good connected.

strange because sometime the systems runs for 15 till 30 min and sometimes its runes like 3 till 5 min.

it seens like strange things to me compard with the pc?

If it's not the fan, then I got no clue since I don't get to try it myself.

 

yeah i know.

the cpu working 50 till 100%.

still at 64 degree so hot isnt it any idea?

Sounds like your motherboard or something is just broken to me. But I'm not an engineer or anything, I just play around with computers as a hobby so my opinions are pretty much nothing indifference to others.