boot problem with inspiron 1520

i discovered a problem with my refurbished inspiron 1520 that i just bought....when i use battery power, it will not boot into windows.. when i use the ac adapter, it does boot into windows......on battery power, it will get to the screen with the bar going acrosss, just before windows shows up....what is causing this.?

 

Take a picture of this bar?

Also, isn't this a contradiction: you say that you can't get into Windows on battery, but they you say that there's a bar across the screen... before Windows shows up? What exactly happens when you try to boot from the battery?

 

thanks for trying to help...the inspiron 1520 would not boot into windows on battery power...what i am saying, after post, and then you get the first screen in windows, that has the bar that goes across the screen, just before it initializes into the desktop screen....i could not boot into windows in safe mode either, so i am thinking the laptop has some sort of hardware problem . i replaced the cpu it came with , got a rma , and sent it back to dell. i put a nividia sticker on the case,,,hope they don,t say anything about that, they should be able to remove that.....sent a letter telling them i did not want to take sticker off in fear of scratching the case, and told them of the problem booting with battery. ..will probably get another after they refund me my money.....someone was telling me to stay away from the 8600gt,,,i just don,t see it as a major problem .or is it worse than i think?