Processor is old can not find new

Check out Newegg or TigerDirect for new PCs....they usually have reasonable prices. If you can tell me the processor brand and model, I'll see if I can locate one for you.

I looked up the HP Pavillion a1229x from HP's website.Here is the CPU
Athlon 64 3400+ 2.2 GHz
1600 MT/s (Mega Transfers/second)
Socket 939
Here is the motherboard it uses
Manufacturer: ASUS
Motherboard Name: A8AE-LE
HP/Compaq motherboard name: AmberineM-GL6E

Here is an old link
http://www.tomshardware.com/forum/171501-30-a8ae

Here is another one
http://h30434.www3.hp.com/t5/Desktop-Hardware/ASUS-A8AE...

You might be able to upgrade the CPU with a more powerful Socket 939 one however some of the faster dual core models even used can be very pricey (not worth it).
However you should have no problem finding a Socket 939 Athlon 64 3400+ CPU used at ebay,maybe at Amazon or at a local computer recycling type store.
Even I have one.That's of course if you are sure that you perhaps broke a important data pin on the CPU.Many times by removing a CPU improperly you could also have wrecked the soldered socket as well which would mean that you could possibly have wrecked the motherboard.
If you feel that you only broke some pins on the CPU then buying a used working CPU shouldn't be a problem.

It's an obsolete PC anyways and you can also build a budget system instead that would be far more powerful.

Socket 939 huh? Honestly I wouldn't bother. Since you're going to keep it anyway though, you should go on eBay to get a new CPU. You can get a dual core CPU for it, but for that price you could get a newer AMD CPU/motherboard/and RAM. Stick with the cheaper single core CPUs or consider replacing the CPU/MB/RAM all together

I should add that if you bent the pins by pulling the heatsink and CPU out of the socket improperly, you may have damaged the motherboard socket as well, in which case a new CPU 939 CPU still wouldn't boot up.

Depending on where you're from, you can get a new Athlon 64 3400+ for as little as $15 used on Ebay....