If continuous series of beeps, remove and reseat memory. What PSU, the 4200 uses more power than 3500. Try disconnecting HD and optical drive to reduce power consumption. Where did the new CPU come from? Try replacing original CPU, if it works, the new one is faulty, or PSU is dodgy.
As it turns out, the problem was that I had moved some of my RAM around( putting two new chips in place of the stock ones and moving those to the expansion slots), which my computer did not like for whatever reason. After reading Mike99's post about a potential memory problem I moved the stock modules back to their original slots and put the new chips in the expansion slots which worked perfectly. Now the system boots promptly and there are zero issues. I want to thank everyone who took the time to post--especially Mike99-- for helping a noob out . And for anyone reading this, remember to replace one component at a time when upgrading so you can narrow down potential issues.