yet another boot problem

hi guys hope you can help me with this, im puzzled.

my brothers got a amd2200+
512mb ram 2x256
redion 9600 pro had it for 3 months
40gig wd ide
he resinly moved his computer to another place to find theres no outlet near by so we used an extion cord to plug in, the cords about 20 ft, when ever he boots now, the ccomp turns on no bios beep no monitor
turns off boots again gets the beep but no monitor desply agai
3rd trime turns on works great
now im thiking that the extention cord may have lowered the voltage comming from the outlet im in the usa so we use 120 volt ac at 50hz so ccould be anychance the voltage could be playing with this maybe noking it to 100 and skresing the psu into thinking there is a prob and putting it in safty
i check the voltage i bios and his 12 volt is at 11.61 whitch seems low


his comp also crashed randomly and on boot he gets a ati radion error by windows saying it caused the reboot

sorry for the ong post i just want to clear this up

More likely something got disturbed in the move. Check that everything is correctly seated and the cable connections are firm.

i have check that but thank you for the responce ironduke, im thinknig the psu might be at fault and would explan THE large dip in voltage. im still oped to suggestions

Make sure you aren't using a POS PSU. What wattage of PSU are you using and maker?

i got no idea of the psu in there because the computer was an eem build made by a co named powerspethe computer has been fine till now so unless its failing i cant see the problem with it, if it does fail i got a psu that came with my case its a cooler maaster 380 watts whitch i will use if its repets again, today it weas fine but it has cycles like that where tis fine and then has a prob
thnaks for the help