As far as I know the 6200's never came with a molex power connector so there shouldn't be any issues that I can forsee. It should draw its power from the AGP slot just like your FX5200 did.
 
How much are you paying for the 6200 tho? These cards are pretty rare nowadays and can't be too cheap, it might be worth investing in a new system. If that is out of the question, atleast check out the 6600's as well. I am pretty sure they can be had for around the same price of the 6200's and will perform much much better.

Nice! An 8 year old PC still trying to get some life out of it... LOL
 
AGP 3.0 came out around 2002, that PC is from 2003.

Also in specs he listed via cnet.
3.0 (total) / 1.0 (free) x AGP 8x - DIMM 184-pin
 
Here is the one you want:
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130654
 
 

_Nite_

sure the pentium 4 systems are still useable, I have a P4 2.8Ghz system under my desk, It be a good retro system. I need to get some more Ram a better AGP card for it though as well. (currently only has 512MB ram and a GF4 MX440 LOL)

 
There was a guy selling like 4x1GB of DDR 400MHz ram on the marketplace for like 17 dollars. They made AGP all the way up to the ATI HD4000 series.

Like I said, money is tight. If I had the $ I'd build a new rig... But it does what I want it to do.