You're in the right place to ask this sort of thing here, much better than editing similar questions into a deleted post which only you and the Moderators can see anyway.
The most basic answer is that your answer was deleted because it was not an answer, which you are already aware of. As such it was flagged by another user of the site (actually it was flagged twice by different users) which brings it onto our review queue. @bmike was merely the first person with the authority to handle the flag who saw it, and he removed it as per our posting guidelines, because answers that are commentary/discussion/me too/thanks/another question etc are not valid ones, and he indicated as such in a comment to explain why he removed it. I just need to make sure you understand that an Admin didn't "just come along and remove it" for no reason, it went through our proper flag and review process, and I would have reached the same conclusion and removed it also.
Now, as for why you had to do it this way because of your low reputation score, that's another story. I have to disagree with you when you say "It doesn't make sense and works against the boards intentions". To my mind, it makes perfect sense, and that's only partly because I get to see everything that is posted, including all the stuff we have to remove regularly to keep the site on topics and used as it is meant to be used. It takes very little effort to earn enough rep to be able to vote and comment, and you should really try to gain these privileges in order to then progress your own questions properly. The privileges are earned in a way that allows you to contribute properly and to guide your contributions to ensure they are appropriate by not allowing your to, for example, engage in lengthy discussions in comments (Not saying you would have, but it happens, and when such stuff is then subsequently flagged, I can almost guarantee it's a low rep user who hasn't quite got it etc). Making you earn your privileges avoids a lot of clean up required by the Moderators.
Now, finally as to the existing answer, and why it wasn't removed you just need to consider that when a contribution is flagged, there is no requirement for whichever of us volunteer Mods to then go and perform a full audit of the Question and all it's Answers that haven't been flagged. It's there still because no-one has flagged it, because it's got votes, and because while it's not a solution to the OP, it is still a valid answer to my mind. If you don;t think it is, you only need 15 rep to flag it to us in the same way your post was flagged, and we'll review it. Please consider that this isn't a personal tech helpdesk service where we have to answer your question the way you want it in a "customer is always right" sort of scenario. Everything on the site, from the moment it leaves your keyboard, is community owned and community edited and moderated. While the answer might not be what the OP and yourself are looking for, if we feel it may well help other people in the future, we can leave it there. The community will up and down vote and flag as appropriate to ensure that answers are useful overall, and very often a *"You can't do that" is appropriate. In this particular scenario, while I imagine that a couple of people may have the skills to identify and solder individual components onto a motherboard without damaging it, I imagine there are also a lot more people who would appreciate being told that this is the only way and the replacement at a part level is maybe a better solution for those of us without mad skills with the flux.
Anyway, I hope this explains the general reasoning behind why what was removed was removed, and why what is still there is still there. Please just take the time to look around for a couple of questions to answer. Just 2 upvotes will give you more rep to do more things on the site.