Recommendations for Computer Repair Kits?

lpq asks: "I've recently starting doing some computer repairs and don't feel organized when it comes to tools. I'm wondering what any people who do computer building/repair use for a portable kit? Are any of the toolkits any good? Or are they just cheaper tools than I might already have with a cheap vinyl case? I saw some expensive kits -- but it looked like one of the main difference is rather a driver device with scads of fittings, the more expensive kits seem to go with separate tools. One had 15 socket screwdriver type tools where I get the same in less space with a ratcheting screwdriver and an adaptor for sockets. I noticed many kits with soldering irons -- not something I've had a need for in most computer upgrades / repairs. Ideas? Basics things to have?"

Comments

tom's recently ran an article about this

[Gregory S Patterson]

Tom's Hardware

I don't think many of us need all the stuff this guy carries, but it's a nice article to get you started.

I recommend

[Professor Collins]

Any plain-Jane kit you can buy at your local Radio Shack or Fry's. There's really no need for an extravagant repair kit. You just need: various screwdrivers, a grapler to get out-of-reach screws, and possibly an IC remover. Not much else to say about repair 'kits.'

Re:I recommend

[walt-sjc]

The problem is that those kits come with crappy / useless tools. The damn things are made with really soft steel, and have crappy handles. The first tough screw you run into ruins the screwdriver. Get some good Vermont American or high-end craftsman screw / nut drivers. Buy them individually, cause you only need a couple of the smaller ones. You also find that you need a few other things that these kits don't have.

Get a good 1/4" driver handle (magnetic) and a bunch of bits (good ones), with hex heads, torx, phillips, standard, security/tamper-proof bits - real handy. (see http://www.wihatools.com/pro_BitSets.htm BTW, Wiha carries ESD safe sets too.) Even though these sets come with phillips / slotted bits, make sure you get NORMAL screwdrivers as mentioned above. Trust me on this. You end up using your #2 phillips and 1/4" nut drivers more than any other tools in the bag.

Another "nice to have" is a little cordless screwdriver.

I've NEVER used an IC remover in the past 8 years. Everything is surface mount anyway. I guess they may have been useful in the 8088 days when memory was socketed chips. Soldering irons are just as useless. Some of those kits come with those crappy vaccuums - don't EVEN bother. Those things are a joke.

Throw in a good wire cutter, needle nose, bent needle nose, normal pliers, telescoping magnetic pickup, dental mirror, small flashlight, anti-static wrist strap, and that should do it for a good basic set for PC work.

For supplies, a can of Air, wire ties, motherboard-sized ESD bag, electrical tape, and anti-static cleaning wipes.

Past that, it depends on exactly what you do. Do you need to make custom RS-232 cables? Network cables? Fix / clean a printer? A good IT tech usually has quite a few tools as he ends up working on just about everything.

Don't buy a pre-made case kit right away

[dnight]

Get a $5 cheap kit, and make note as you go what tools you need, and aquire them. Jensen Tools is a good place to check out. Kind of pricey, but a pretty good selection of tools,. test equipment, etc.

pretty straightforward

[tps12]

Lots of geeks swear by those all-in-one tools, but with those you usually get the lowest common denominator for each tool, and a bunch of tools you'll never use. I'd recommend just hitting your local hardware store and freestyling it. For a few bucks you can get a decent hammer, crescent wrench (get one metric and one standard), and small saw (unfortunately, many cases and motherboards aren't actually built to standard dimensions). That should be all you need to get started. If you don't have an antistatic leash, you can make one out of a strip of duct tape. Tape one end to your wrist and the other end to something large and metal (I use my car, but metal shelves should suffice), and you're set.

Re:pretty straightforward

[n9hmg]

He forgot the striped paint.
You did understand that he was joking, right?

Been there, done that, here's what you need:

[itwerx]

- A screwdriver with #2 Phillips, flat and assorted Torx bits
- A small set of little-tiny screw drivers for laptops
- A penlight
- A telescoping mirror
- A telescoping magnetic pickup or grabber
- A big (40+) CD case to carry all your utility software
- A couple of blank floppies
- A '98 boot diskette (for machines that won't boot off CD-ROM for whatever reason)
- Spare IDE/FDD cables
- Spare SCSI cables and terminators
- Spare Cat-5 cables of various lengths including one short cross-over and a couple of inline couplers so you can daisy-chain them

And if you still have room: a mini-hub, spare NIC, spare video-card, HDD for imaging, laptop with PCMCIA nic and modem

Enjoy!

Quality over gizmos.

[Jonny 290]

My kit (when I finish it) will consist of:

• Craftsman screwdrivers (large, medium, small, in flathead, Phillips and Torx)
  
• Hex wrench set
  
• Gerber multi-plier (flat-nose)
  
• Craftsman diagonal cutters, end cutters, straight needle nose and bent needle nose pliers
  
• Quality jeweler's screw driver set
  
• Requisite Altoids tin or film canister full of screws, jumpers, etc.
  
• Weller pencil iron (you may not need it for a HD swap, but when you're doing a watercool job or fanbus it's critical) with silver (small diameter) and rosin-core (larger diameter) solder
  
• DMM - even a $30 eBay special can test continuity, LED's, ground paths and PSU voltages.
  
• RJ45 crimpers (quality) with an assortment of RJ45 and RJ11 ends
  
• 2AA Mag Light with extra batteries
  
• Medium size (8 inch) vise-grips (Please, get the name brand. :))
  
• Shrink tube in 1/2", 3/8" and 3/16" (preshrunk sizes)
  
• Cable ties (4", 6" and 8")
  
• Canned air (cleaning, and if you turn it upside down you can use it as freeze spray and isolate components that are having heat-related failures)
  
• Bonus points for a TP cable tester, signal tracer, heatsink compound, Loctite, Dremel with bits, and super-glue (to counteract the previous Dremeling :)).
  

Re:Quality over gizmos.

[Bald Wookie]

Canned air (cleaning, and if you turn it upside down you can use it as freeze spray and isolate components that are having heat-related failures)

You've got some good stuff in your kit, but this one scares me. A nice thick layer of frost on your electronics is a great way to release the magic smoke. Plus I can't imagine the thermal shock is good for your components.

I can't say that I've seen too many heat related failures on stock hardware. Overclocked stuff, sure, but not your typical business computer. The few times I have, it's always been pretty obvious. Dead fans, computer buried under stuff, dead AC in the server room, that kind of thing. Certainly nothing I'd hit with a refrigerant just to see if it made a difference. Of course, I've also never gotten a paying gig to put togeter a water cooler or a fanbus. Maybe you're just having more fun.

I'd add a mirror or two to the kit. Maybe some duct tape. A punchdown tool for doing phone wiring is also handy (if you ever get stuck doing that sort of thing). One of my favorite tools was a nice hand cart. Nothing like moving five systems without much effort. On the softer side, a blank floppy, a couple of CD-R's and maybe a USB keychain drive might be useful. Sometimes you can't get the NIC working without sneakernetting something over. A good pocketknife can also be useful for quick jobs and cuts that you cant make with snips. Throw in some cables, adaptors, gender changers and you'd have a pretty solid kit.

Compared to auot mechanics, IT guys get off pretty easy. A hundred bucks of tools is almost overkill for a PC. That wont even get the sparkplugs changed on some cars. Experience will tell you what you need, what to buy, what to improvise and what you can't live without.

Basic tools to have:

[joeface]

My most-used tools:

Screwdriver with swappable magnetic bits. It's murphy's law: when the screw falls, it will fall into that one corner of the case that you can't reach.

Flashlight. Preferably a mini mag light. They're bright as hell and they're easy to hold in your teeth when you need both hands =)

Paper Clips. They're impossible to track down whenever the CD drive gets jammed, so you'd better have one on you.

Dentist's mirror. To read the serial number or FCC ID on that card that you're too lazy to pull out of the box.

Sledgehammer. For those really frustrating projects.

This is all pretty common-sense stuff, but with the exception of the sledgehammer, most of the jobs I do get done with those tools.

Re:Basic tools to have:

[goldmeer]

Flashlight. Preferably a mini mag light. They're bright as hell and they're easy to hold in your teeth when you need both hands =)

Forget holding it in your teeth. One of the best signs of a true tech-geek is use of something like this:

http://www.orderoutdoors.com/niteize/hband.htm

Not only is highly functional, but it repels chicks better than a pocket protector. (Don't let the picture of the female wearing this item throw you off, she was PAID to have her picture taken with it. I'm not convinced that it isn't a retouch job)

Re:Basic tools to have:

[Matthaeus]

The only thing in your computer that's sensitive to the sort of magnetic field a magnetic screwdriver has in it is the hard drive. Which is conveniently enough encased in a shield of pure metal through which a magnetic field cannot penetrate, and contains within it magnets quite a bit stronger than anything you're likely to find in a screwdriver. Now that nobody uses floppies for anything permanent anymore (you are backing up your floppies before you mod me down, aren't you?), the paranoia about magnets that we all learned in the early nineties is not as justifiable.

Floppies, Zip discs, and your monitor are the only things in your computer that would possibly react strangely to a magnetized screwdriver.

One of the most useful $US5.99 I ever spent...

[devphil]

...was for a metal dish, with high walls, about six inches across, with a very magnetic base. It sticks to metal, and any screw or latching piece will stick to it. No more building a little pile of tiny screws as I take apart a computer while hoping they don't roll away or I knock them over.

It's for home, but I'm thinking about getting another at work.

Re:One of the most useful $US5.99 I ever spent...

[larien]

Cool idea, I'll have to keep my eyes open for one, as I've also had the same issue with screws. Just watch where you leave it (i.e. keep it away from any floppies or hard drives!). However, it does lead to another "essential"; a mix of screws used in computer cases. Most fall into about 3 categories so keep a selection of these. If you ever buy a computer case, you'll probably get a pile of spares, so keep them handy in case you (or someone else) loses the screws.

Added to this, get some spare PCI blanking plates; if you work on servers, you'll probably remove cards at various times and then you usually have to leave a gap at the back which (a) screws up airflow and (b) lets dust in.

Re:One of the most useful $US5.99 I ever spent...

[devphil]

The dinky little "computer toolkit" I have fro years back has a nice translucent plastic tube, about 3/4" diameter. Holding about fifty screws and jumpers and whatnot right about now. I agree -- they're essential.

Re:One of the most useful $US5.99 I ever spent...

[devphil]

now when you go to screw in your harddrive your screws will ALREADY BE MAGNETIC YAY

Wow. I've never seen anyone flunk "Intro to Remedial Physics" as fast as you just did.

Re:One of the most useful $US5.99 I ever spent...

[Matthaeus]

Just to clarify:

The metal case around a hard drive works as a magnetic shield. Since it's nonferrous, the magnetic field can't get through. Which is why the incredibly powerful magnets inside the hard drive can't be detected outside the case. Ever noticed how you can put a floppy drive on top of a hard drive and have it work just fine?

I read that as:

[gnovos]

"computer repair kilts", and I was wondering if I had missed out on yet another fashion trend...

Parts, parts, parts

[DavidYaw]

Personally, for tools, A screwdriver is ususally enough. (Get one of the four-in-ones.) The only other tool I'd add is a mirror. (Get an old makeup mirror, the kind that's in a compact that had makeup on one side and the mirror on the other. It keeps the mirror protected. I got one from my mom when I was in high school, works great.)

The most important thing is parts. Gonna throw away that old 386? Take out all the screws, IDE & floppy cables, power supply cables. (And sort the screws by size.) Add a couple network cables, maybe a USB cable, and a power cable.

A couple boot floppies for various OSs (make sure they've got CD drive support), and that'll do it.

What utility software?

[itwerx]

I hear you ask...

'98 boot disk (and bootable CD)
Spinrite
MemCheck
CheckIt/QAPlus
pcAnywher e
VNC
WinZip
Acrobat
DOS version of PKZip
Collection of common nic/video/printer/etc drivers
Copies of major OS's (Win2K, 98 OSR2 etc.)
Copies of Office
Copies of SP's and patches
Copies of browsers (IE, Netscape, Opera)
L0pht Crack
Your favorite IP scanner and other IP tools (e.g. Putty)
Other tools depending on OS's you work with (e.g. JCMD for Netware, Upromote for NT, the Win2K/NT resource kits, 'Nix boot disk and utils and hundreds of other favorite need-specific utils)

Re:What utility software?

[walt-sjc]

Add to that:

Tomsrtbt floppy
Linuxcare Bootable Business Card CD
Ghost
Paritition Magic

Re:What utility software?

[SpaceLifeForm]

I'd also add a MEMTEST86 bootable floppy.

Re:What utility software?

[z84976]

spinrite! ahh what fond memories I have of letting old seaget st-251 mfm drives rumble away for days straight trying to recover data from university professor partitions scrambled by the likes of stealth_c and form....

Stuff I forgot to list

[itwerx]

- Spare screws and jumpers of all sizes
- Needle-nose pliers
- Canned air
- Cable tester and fox-and-hound (tracer)
- Spare power/usb/parallel cables
- Wooden pencil or tongue-depressor (for cleaning mice)
- Paperclip
- Pen
- Sharpie permanent marker
- Assorted gender changers
- SCSI cable adaptors (e.g. 68F-50F)

Probably more stuff...!

Too late

[0x20]

The days of serious homebrew computer repair are over. Regular soldering irons are too big to do anything but burn out your components and besides the only replaceable part of a motherboard these days (besides the cpu) is the bios chip, which can be removed without soldering. If anything seriously breaks, you're going to need to replace the whole piece anyway.

So you don't need any special tools. I've been repairing PCs for almost 20 years now and it's extremely infrequent that you need anything outside this list (and you shouldn't go beyond these tools without some electronics training anyway):

• 1 #2 phillips-head screwdriver with magnetized tip (removes almost every screw in a modern PC and no, you can't damage anything with the magnet)
• 1 small flathead screwdriver (not used that often, except to remove spring clips on CPU coolers)
• 1 set tweezers or needle-nose pliers (to move jumpers and small wires around)
• 1 set pliers (to remove and install motherboard riser screws, etc)
• 1 flashlight
• 1 small ziploc bag or pill tube to hold extra screws
• 1 grounding wrist strap
• 1 can compressed air (or tiny vacuum)

That's it. Keep them in a pouch if you want. Don't go buying any fancy toolkits; they're for suckers. The only other tools you need are probably going to be software-based.

Re:Too late

[sydb]

Pay heed to the parent.

I've been doing computer repairs for about 10 years. Carrying round shitloads of tools is just a pain in the ass and 99% of the time you don't use them. If you really NEED something you haven't got use your brain and improvise.

The only indispensible tool I have is a screwdriver with a set of interchangable bits.

Don't get me wrong, I've repaired power supplies at component level and yes you need a voltmeter and a soldering iron but no-one needs to do this any more. In the UK a case with a power supply is £25, my time is worth more than this per hour and component level repairs take time. Buy a new power supply.

I would also say, don't get in too deep. This kind of work is fun for a while but I no longer accept requests to fix computers. It's not challenging or interesting or financially rewarding and if something goes wrong I don't want to deal with it (did they take backups? did they really take backups?)

Re:Too late

[ncc74656]

#2 phillips-head screwdriver with magnetized tip

...and if yours isn't magnetized, you can rub it against the speaker magnet (if it's the type where the magnetic material isn't fully enclosed in metal) a few times to get at least a weak magnetization on it. It'll hold a screw long enough to get it into place.

Back when I was digging into computers on an almost-daily basis, I found a Leatherman to be useful. It replaces half of the tools on your list, and you can carry it with you all the time.

First and last choice.

[NoMoreNicksLeft]

Sledgehammer. You don't always need it, but when you do, nothing else can substitute for it.

More detail

[0x0d0a]

I have a little Radio Shack kit as recommended above, which I endorse. Here's my breakdown:

Phillips and flathead screwdrivers, in two sizes each (you need a dinky little pair for some screws).

Tweezers (these can get awfully useful)

Two hex drivers in different sizes (so you don't strip case screws...I love hex drivers).

Torx screwdriver with two sizes of head that doubles as a large hex driver.

Pair of tweezers.

Little gitchie-grabber thingie to grasp tiny parts where your fingers can't fit.

Case to store extra screws and screws in use. Losing screws from the case you're working on can get really, really easy.

The non-useful bits that came with the kit: IC removers. Why the *hell* do they ship IC removers with repair kits any more?

I added the following to the kit:

Pair of forceps. Holding wires or little bits out of the way can come in handy. Fishing/bait kits have these.

Needlenose pliers. Useful for all sorts of stuff. I strongly recommend these.

Here's what's in my kit

[slaker]

I don't do MUCH techwork any more, but unfortunately, I've never in my life actually been able to walk away from it.

99% of the time, the only thing needed, hardware-wise, is a #2 philips screwdriver. For safety and completeness, though, a set of "precision" screwdrivers and at least one smallish flathead are good, too. Lest I forget, the possibility of my patient saying "Compaq" on its chassis also merits my inclusion of #8 and #10 Torx, which are both hard to find.

Very thin needlenose pliers, and a thicker set for miscellaneous bending.
A pair of tweezers.
Dental mirror.
Wire snips.
Multimeter & oscilliscope (er, I keep that one in the car).
Dusk mask and thin, wool painters gloves (screw static, I can touchtype in them and they keep my hands from getting cut).
Bandages (in case my hands get cut) & neosporin.
Canned air.
Wrist strap in case my customer is paranoid or something.
Sears 3.6V cordless screwdriver, if I'm working on several machines that day.
2.5" to 3.5" hard disk adaptor.
Intel Pro/100 NIC
8GB 2.5" hard disk, filled w/ software installs & diagnostic packages.
USB CD-RW
8x Parallel CD-ROM.
An assortment of ribbon cables (IDE, 50-pin SCSI, floppy, serial etc).
A collection of power splitters and adaptors
Socket 7 HSF.
Slot 1 HSF
Slot A HSF
80mm case fan
Floppy disk drive
14.4 USR external modem
Some AA batteries
Keyboards: 1 AT-style w/ PS2 adaptor, 1 USB
Mice: 1 serial, 1 USB w/ PS2 adaptor
A lighted magnifying glass
Spray n' wash (in car) and spray-n-wash wipes
Artic Silver
Deodorant & clean shirt
basically lint-free rags
Crimper
Velcro ties & plastic "zip" ties
Cable tester
4-port switch
Spool o' cable & some connectors
Punch down tool.
Known-good 14" monitor (in car, also) and matrox millenium PCI card.
A wide assortment of RAM (presently: 2x72-pin 64MB FPM, 128MB PC100, 256MB PC2100, 64MB 72-pin SODIMM, 256MB 144pin SODIMM, 128MB PC800 RIMM + cRIMM)
Lots of screws & spare jumpers
Dremel tool

Add to that essentially a complete collection of every driver, operating system or software package I've installed more than once (about 70 CDs, I think), and you're basically set.

I carry everything around in a big, soft-sided tackle box.

Hardware that I choose to carry around is generally on the the basis of very wide support. You'd be hard pressed to find an OS that didn't know what to do with a Matrox Millenium, for example.

Last thing: Big bottles of tums and asprin. Not for the work, which is easy, but for the endless demands from people who realize that you know how to fix computers.

Re:Here's what's in my kit

[dattaway]

A logic probe has been the best tool for troubleshooting my computer problems. It allows for a quick way to see if the clock is enabling an interrupt, a bus, or a decoder chip on some card that seems defective. If it latches the light, you know your suspected card has been activated and is seen by the operating system.

This $20 tool can catch an event so small that something like the eyes of an oscilliscope would glaze over.

Watch the quality/warentiee

[bluGill]

Sears Craftsman tools have a lifetime warentiee, if they break you walk into any sears store and get a replacement no questions asked. Snap-on is much higher quality (in general), but they in general don't carry the smaller tools computers need. Many tools are lifetime warentiee, but you can't find where to get it exchanged.

Don't fool youself, you will need that warentiee. The non-warentieed tools are generally soft metal that nearly bends working air, they have no hope of dealing with a real part. (Okay, not quite that bad, but close enough) With the good tools you won't have nearly as many problems, but you will eventialy break something. I can't say what (other than your #2 phillips) you will need it for, but you will need it for something.

Oh, in addition to the above: a #2 square drive screwdriver. I've never seen the need for one in computers, but if you ever come across the person who designs computer packaging ask them to change. Square drive is a lot nicer than phillips, it lasts longer and takes more torque if nessicary. (Warning, don't over torque screws putting them in, but sometimes you get a stubberen on that needs extra help to come out). Opinion I know, but I think it is a good idea.

Spare screws

[zero_offset]

Everybody is forgetting the "accessory" I find I use the most -- a big old ziplock baggie full of spare screws, motherboard mounting posts (and those square snap-in mounts), washers (paper and metal), and just about every other computer-related fastner you can think of.

How many times have you cracked open a case to discover that every drive was held in by a single screw? Or that screw that the owner has stripped and is relying on it being wedged in just right to hold the $400 video card in place?

Of course, it's easiest to acquire these items by simply collecting them over time. That would be a cool thing for an online retailer to sell. "500 piece miscellaneous computer fastner pack... $7..." :)

Oh yeah, in case nobody said it: zip-ties and velcro tie-wraps...

Cordless screwdriver

[Quill_28]

A nice small cordless drill works even better must have a clutch. Carry around bits, like phillips head, torx, etc.

POST card!

[ivan256]

I'm surprised that NOBODY has suggested a POST card!

These are invaluable for reparing dead machines. If the machine is dead, you will never have to guess at the problem again. You plug one of these into an expansion slot (PCI in the case of the one listed above), and it displays the POST codes that are generated by the BIOS as it tests each piece of hardware. The one it's displaying when it gets stuck can be looked up in the book and you know what piece of harware is bad. Best $100 you'll ever spend if you fix alot of machines.

What is it with you people?

[adolf]

What sorts of computers are you people working on, which require the use of dremel tools, pliers, portable bandsaws, and a half-ton of various and sundry other tools? I've got a lot of this stuff, myself, but I don't want to tote it all around with me.

When I work on computers, I carry with me a Craftsman #2 phillips screwdriver and a folding pocket knife that is just a hair too small to be considered a concealed weapon, with a very sharp, half-serrated edge.

I've seldom needed anything else. Hardware diagnosis generally doesn't require a working spare of every part of a PC, and the parts themselves are generally too cheap individually to bother with fixing them.

Turn it on, nothing happens? Make sure power button is plugged in and things all look right. Else, the motherboard -and- PSU are both highly suspect and should not be trusted.

System boots, but without video and monitor does not turn on, optionally with POST beeps? Re-seat video card, else replace. Monitors generally show symptoms long before they bite the dust, so if it's a toast CRT they've likely known about it for a very long time wouldn't have called you to help them in the first place.

POST beeps, or everything spins up but nothing else happens. Funky RAM. Re-seat, and replace. Same symptoms with a flamed CPU, but that normally doesn't happen unless the fan is not spinning or has obviously bad bearings.

No sound? Re-seat, and then try software fixes. If still broke, replace.

Customer fucked up a BIOS flash? Remove BIOS with careful application of aforementioned knife (this is where a stout blade is important), install in a live system, re-run the appropriate flash utility, replace everything where it belongs, and you're golden.

New hard drive? Grab jumpers between knife point and appropriate finger of same hand - no finger nails required.

Computer works fine, but eventually becomes flakey? Suspect software. If not software, then heat. Find things that are hot and just look and see if there's anything physically wrong with them - like, say, the audio cable from a CD-ROM drive being crammed under the sound card into the 16-bit portion of an ISA slot. Or a component which has a large brown circle around it on the PCB - obviously something which is, or has been, Way Too Hot. Whatever part it's attached to gets replaced.

I'm not going to disassemble, for instance, a CD-ROM drive on-site. If anything, I'll diagnose it as toast, and have them buy a new one. These parts are worth too little to troubleshoot and fix when paid hourly.

The point is this: Don't bother carrying more than you need. I've got a small bag of screws and various other case hardware in the glovebox of my car, and it generally stays there.

Supposedly, certain Compaq machines require the use of a Torx driver to get into them, but I've never seen one. I only work on computers as a favor to people that I know, at least in passing - and these people don't buy Compaq. If I ever find one, however, I've got a wonderful set of 16 security Torx bits that I found in the junk bin at a hardware store for $1.50. It stays at home where it belongs, alongside the dremel.

Anti static mat + wrist strap + grounding kit.

[Alex]

When you remove these components where are you going to put them? If you want to keep them safe, you will want the above.

If in doubt read the preceding /. thread about static - I'm shocked (but not surprised) that no one has mentioned this.

Alex

Re:The Wave

[Webmoth]

I lost mine and I miss it sorely. :-(

My kit

[Webmoth]

My toolkit contains this stuff:

An Ideal Zip-Kit tool bag

A Palladin Tools crimper with RJ-45 die (don't go cheap on a crimper, otherwise you'll be uttering bad words). You might want an RJ-11 die for phone cords, but that's up to you.

A tool to strip the outer jacket of cables

Punchdown tool (for RJ-45 jacks & patch panels)

Screwdrivers: #2 Phillips (you'll probably never use a #1), 3/16" Flat, assorted Torx.

3/16" nutdriver (for those hex standoffs on DB connectors)

Spare parts: RJ-45 connectors, screws (there's 2 sizes in computers, generally), expansion slot blanking plates.

Band-aids. Computers often have sharp edges. A towel to cry in when everything you try doesn't work (j/k).

Pliers: needle-nose, side cutters. Scissors.

Can of compressed air. Tube of heat sink compound. Permanant markers, red & black (Sharpies work well). Roll of electrical tape.

Flashlight. A small LED light on your keychain also works well.

A multi-function tool (like a Leatherman) in your pocket for when your tool bag isn't handy. Mine's lost, if you find it let me know.

A cable tester is nice to have.

CD case for all your utilities discs. A Windows 98 boot floppy. A Linux rescue disk set if you are adventurous.

One more thing

[Webmoth]

Nylon cable ties. These are your friends.

Nobody mentionned ...

[Etyenne]

... a small paintbrush. I am using this to dust off part. It's cheaper (and more environnement-friendly) than canned air and does the job just as good (with a tiny bit more effort).