Dell Inspiron 640m won't boot

[Kristy]

I have a Dell Inspiron 640m that crashed the other day. The blue screen had _IRQL_NOT_LESS_OR_EQUAL error code. At the time I didn't have time to figure out what was wrong so I shut it down and returned a few hours later to run diagnostics. However when I tried to boot it up, it wouldn't load past the Dell loading screen and I couldn't access diagnostics. I turned off and tried it again and now it won't boot anything. All I have is a black screen. The CD drive and fan will click on for a second and then immediately turn off. I tried running the reinstallation disk but nothing but black screen. Someone told me to try taking the battery out and reseating it so I did that this morning and now it is still not booting up (black screen) and I have a new problem. This time the fan and power light came on when I tried to start it but when I tried to shut it down I can't get it to shut off. Holding the power button does not work. The fan has been running for about 3 hours today with no signs of stopping. I unplugged it thinking the battery would die and at least shut the fan off but the battery should have died by now and it is still running. I don't want to do any further damage (if that's possible at this stage) so can someone help!

Some background information on this computer: This is the 4th time this year that it has crashed. The last time the tech installed a brand new hard drive. That was about 5 mo ago and it has been running fine until the other day. I have already put a ton of money into it and don't really want to invest anymore in a lost cause. Should I just give up and plan on buying a new laptop or can this one be saved? Thanks!

 

[Tmagic650]

Remove the hard drive and see if the laptop will start up normally to the point of hard drive detection. If it does, the hard drive is bad, once again