I have heard from many different sources that crappy third party controllers can easily blow out ports on your Dreamcast.
What I found out yesterday was that even an official Dreamcast controller can do this. A first party Dreamcast controller I had recently bought was faulty and blew out the F1 resistor in the controller board. That means that NONE of the controller ports will work.
Here is the culprit. I bought it from a thrift shop the other day.
I suppose it's live by thrift shops, die by the thrift shops. But there are two ways to look at buying Dreamcast stuff from pawn shops, Salvation army, "boot sales", garage sales...ect.
A. - Most people won't resell or donate electronics that they know are faulty.
B. - Most people are jerks or too stupid to know that the stuff they are selling is faulty.
For me it's a moot point. I only paid like $10 for the Dreamcast I blew up because I got it at a garage sale. I could have paid more for stuff from Ebay, but are electronics purchased like that really safer? It's debatable.
Anyways you can buy a new resistor to replace the one the faulty controller blew out. It takes a bit of time and RISK to your Dreamcast. Some people have had better luck than others.
Here is a nice little guide from the Devcast site:
And here is a little blurb from the Dreamcast Scene Site.
There is also a less safe but easier way
I do not suggest that anyone tries this. You can hurt/kill yourself if you don't know anything about electronics (I was supposed to unplug it?!!?!?) and you can easily damage your Dreamcast beyond all repair. It involves using a bit of wire to directly connect the legs of the busted F1 resistor.
I am mainly putting this up so people get a little better picture of what the F1 fuse looks like.
Basically the Dreamcast is very easy to crack open. You just need a regular Phillips head screwdriver.
Take out the 4 screws then flip it over to remove the top.
(or an official controller that's faulty)
My crappy fix actually seemed to work. However, this Dreamcast might now be the largest fire hazard in my house. Plus if you ever use a faulty controller in that Dreamcast it might just blow out the whole thing...
So it's a bit hard to fix this if you are not used to it. Buying a new resistor isn't expensive but you will need a soldering iron to get the old one out and replace it.
It might be a better idea to simply buy a replacement controller board or even a new Dreamcast.
In conclusion beware of trying out new controllers! If you happen to have two Dreamcasts don't use the nicer one to test out controllers for the first time. And yes, even official Dreamcast controllers can ruin your controller ports.
All in all I suppose that it's a good lesson to learn. Even the Dreamcast can fail (though it's pretty damn simple to try and fix it).