Our latest donation is an Inspiron 8500. When I power it on, it occasionally will get to the logon screen. Most of time, all I get are vertical lines and bars, lots of weird colors and error messages about turning off the computer immediately to prevent damage. I tried to get into safe mode but haven't been able to so far. I thought the problem might be a display driver problem. However with the intermittent boot, are we more likely looking at a hardware problem (expensive repair)? When it doesn't boot up, the power light is on but I can't hear the hard drive or fan.

Sounds more like the video is bad.

If you have one I would try a video card and a power supply.

Also try all the normal stuff like reseating components and cables, clean out the dust bunnies, etc.

If I remember correctly there should be diagnostic lights on the system, either on the front panel or in the back on the i/o shield somewhere. If so what state are they? Green, orange, off?

I was finally able to get into safe mode so I'm 95 percent sure it is the card. I found a great tutorial and it looks like it will be pretty simple to install a new video card with a little patience. Now I just have to find a card. Once that is installed, I will worry about the intermittent boot.

Once that is installed, I will worry about the intermittent boot.
The problems could very easily be one and the same. Not necessarily, but very possible.