I have a DELL LATITUDE D630 with Mint 17 that I bought at Free Geek (in Portland) and that I'd been using for a year or two doing basic stuff like word processing and surfing.
Now I need to do some python and stuff, and I plugged in a USB mouse and started watching these instructional videos. I was online through the network at work. Internet access was fine (wireless); the sound was fine.

At some point, I had to go home. When I took out the laptop the next day, I didn't want to use the external (USB) mouse.

What I've found is that the trackpad, the blue button mousy thingy, Bluetooth, the ability to even recognize such a thing as Wi-Fi, and all sound is gone from the machine.

I searched this forum and found the following:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LUNIX="i8042.reset i8042.nomux i8042.nopnp i8042.noloop"
along with a suggestion to put the "i8042" stuff not there but next to "quiet splash".

I tried both, triumphantly remembering how to use vi and all that.

Nothing changed. (Also, I have no idea what a grub or a splash is, or i8042 for that matter. "nopnp" sounds like we're avoiding a certain kind of BJT, but probably not...)

I've looked at the related posts, but I don't understand what they're saying. There's some code I see suggested, but no mention of *where* that code goes...

Someone else said
"Bootup your machine without the mouse.
Do a "chmod 644 /etc/rc.d/rc.hotplug".
Compile a custom kernel for your laptop...."

I understand the first two lines. What is compiling "a custom kernel"?

Anyone know what else I can try or can anyone explain those missing pieces?

Thanks

If you didn't need the kernel parameters previously, don't go adding them now. Blindly hacking and trying random things without an understanding of what you're dong is likely to result in bigger problems.

Start from the top and show us what is reported by the following commands:

For PCI-connected hardware
For devices connected to the USB subsystem
For the pointing (input) devices
or better still
There may be more questions.

Okay, I didn't think I was doing anything blindly or randomly because I was doing exactly what everyone says you're supposed to do: Look at forums online and try what people there say to do.

Anyway, since you told me that was (against everything I hear everyday) not the way to go, I went to the Linux Foundation class and started trying to learn stuff first. (So far, it's been a great deal of advertising about how awesome Linux is. I finally worked up to some basic definitions and ran out of time for the day.)

So, finally, "sudo lspci -nnk":
There is a whole page of stuff... but I can't get online on that laptop, so I'm typing this on another machine. I can probably take a photo of the result of "sudo lspci -nnk"...

Seriously... I don't know how to get around a catch-22 other than buying another machine.

Thank you for trying to help.

I get that. The real problem is we don't know what state things are in now without asking 20 questions. We don't have the benefit of the thread history showing the suggestions, and what led to those. Definitive commands and output to help diagnose the issue are really the only way forward here.

If taking some photos is easiest for you, then do that. I am concerned that so much is not working on this machine though. That is definitely not a normal situation. One option you might try is booting from a Live distro (USB stick), which can quickly help assess what might not be working (and eliminate the installed OS from the equation). This does obviously depend on what other resources you have available to you. Support from a local Linux User Group (LUG) might also be worth pursuing here. They could probably make quick work of getting to the underlying issues and attempt to resolve them for you.

The challenge of trying to do this on your own while learning Linux can be like 'baptism by fire'. We've all been there as new users.

Well, if wired ethernet is available to you (work, library, home, friend's place), then that can make things a whole lot easier with respect to being online.