In this lesson, we're going to talk about
step three of the troubleshooting methodology,
which is test the theory.
Now, CompTIA writes this down
as test the theory to determine the cause.
Once that theory is confirmed,
determine the next steps to resolve the problem.
If the theory is not confirmed,
reestablish a new theory or escalate,
and this is what we're focused on in step three.
So in step one, we identified our problem.
In step two, we came up with an idea
of what we thought the probable cause of that problem was,
and now here in step three,
we're going to test our theory to see if we were right.
Now, up to this point, we have done
a lot of work in thinking about the problem,
but we haven't done any kind of configurations
or changes to the system to try to solve that problem.
And now that we're here in step three,
we can finally do that.
So let's say for example, we had a system
that wouldn't turn on, well, if we have a system
that won't turn on, it can be lots of different problems,
but we thought the problem was this computer
wasn't plugged into the wall outlet.
Now it's a really simple theory to test.
We can simply trace the cable from the back of the tower
into the wall outlet and see if it's plugged in,
and if it's not, that tells me that was the problem.
Let's plug it in, turn on the computer
and see if it boots up, if it does, that was the problem,
we have now confirmed it,
and our theory has solved the problem.
But let's say we got there and the cable
wasn't plugged into the wall.
We plugged the cable into the wall,
we pushed the power button, and nothing happens.
The computer still won't turn on.
Well, now our theory of it being unplugged
being the root cause is no longer valid,
so we need to now create a new theory.
Based on the different symptoms we had,
based on what we've observed,
and based on what we've done so far,
we know that what we thought was the problem
is no longer the problem, and so we need to figure out
what is the next theory or probable cause
that we're going to attempt.
In this case, I might say the wall outlet
doesn't provide enough power, so I make a theory
that the wall outlet is the problem.
So I step back to step two, I create a new theory
and I say, I think the wall outlet is the problem.
Now I'm back in step three, I need to test that theory.
So I grab my volt meter, I plug it into the wall,
and I test and I see that I'm getting 120 volts AC,
and since I'm located here in the United States,
that's perfectly fine, so that's not my problem.
So I need to establish another theory and try again.
So maybe I think it's the power supply
itself that's the problem.
And now I can use that as my new theory
and start working towards that to confirm it.
The idea here is we guess on something,
we then try to test that theory, and if we test that theory
and find it's not the cause,
we are then going to have to get a new theory.
If we did test the theory and we confirm that theory,
the next steps are going to be to resolve
the problem for the long term.
So at this point, if we tested the power supply
and found that it was faulty,
we would have now confirmed our theory,
and at this point, we would then need to determine
the next steps that we have to resolve this problem.
That could be fixing the power supply,
replacing the power supply,
or maybe even replacing the entire computer
depending on how old that unit is
and what your corporate policies are.
Another thing to keep in mind here in step three
when you're testing the theory to determine the cause,
is that you really have four possible outcomes.
The first is that your theory is confirmed,
and in this case, you're going to take steps to fix it.
The second is your theory is not confirmed,
and you need to come up with a new theory
and then try to test that theory,
and if you find it, then you're going to fix it.
The third is you identified the problem,
you've tested your theory
and you figured out what the problem is,
but you don't have the skills
or the authority to fix that thing.
For example, maybe you've identified
that this particular fix is going to require a $10,000 part,
and you're not authorized to replace
that part in that system.
Well, in this case, you'd have to escalate that up
to the team that's responsible for that server
or that piece of equipment, so they can then replace
that part or they get the approval to replace that part.
Another side of this might be you don't have
the skills to fix that thing yet.
Maybe you found there was an issue
that was happening across multiple systems
that you're supporting, and when you look at it,
you figured out that the issue had to do with a group policy
that was being pushed out from the Windows server.
But you don't work in the Windows server group,
so you're going to have to escalate this issue
over to the Windows server group
so that that team can change the policies
and configurations that they're pushing out
to all the systems across the domain
and fix this larger problem.
Another issue might be where you have to escalate this
and bring in some outside support.
Maybe you found out that the reason this system
isn't working right is that it was infected by malware
or there's an attacker in your system
and they have control of that system.
In that case, as a technician,
we are probably not going to be the ones to fix that,
but instead, we're going to call in the cybersecurity experts
who are going to come in and kick those bad folks
out of our network and off of that box
so that we can gain access to it once more.
Again, a lot of this is going to depend on your organization,
the policies, procedures, and authorities that they give
to the technicians at different levels.
But keep in mind that one of the things you could do
is escalate this when there's an issue.
Now, the fourth possible outcome
is that you tested your theory,
you come up with a bunch of theories, and you're just stuck.
You don't know what the right answer is,
you don't know how to fix this problem.
And in those cases, you would again,
need to escalate this to the next higher level.
In most organizations, we have a tiered support structure
of tier one, tier two, and tier three support technicians.
Tier one is going to solve all of the most basic problems.
Over time, you're going to gain more skills
and you'll move up to tier two
where you can solve some more advanced problems.
And we get to tier three, that's really where you start
dealing with the subject matter experts,
people who are the system administrators,
the server administrators, the cryptographic
and cybersecurity experts, and things like that.
Now, over time, you may move into those positions,
but today, when you're first starting out,
you're probably going to be in tier one or maybe tier two,
and so there are going to be some things
that you just don't know how to identify or how to fix,
and in those cases, you're going to want to escalate
those tickets up to tier two
or tier three for additional assistance
so they can solve the problem for the end user.