startup problem solved - for now...

My G5 froze at startup after the startup chime, with the Apple logo on the screen.

I tried a few things:

I replaced the battery, reset the PMU, started up with just one HD and then the other, started up with Command-Alt-P-R, and started up in safe mode.

The last thing I did was clean the memory cards and heat the card slots with a hair dryer. And with the alt-key pressed down it started up - very slowly. I only had to reset the time.

Now that it is working what do I do next to keep it working?

I have a lot of work to catch up on so I feel a bit pressed.

I have the install dvd in an external dvd drive. I also have another complete G5 that doesn't start up.