Dear readers - over the years, I've had a variety of repair projects, some of which required "field repairs."
Recently, I've decided to catalogue it, in the hopes that perhaps, it might just come in useful to someone.
As I presently find myself in a small Eastern European republic, with rather poor access to repair materials for computer systems; and I make a bit of a side income doing these repairs, I find myself using some of these tricks more than ever before.
I've found that, when incredibly short on something as crucial as thermal paste, a temporary substitute may be made with the use of petroleum jelly (Vaseline), and graphite from a pencil. While the clay does act slightly as a thermal insulator, I find that, when sufficiently powdered, and combined with petroleum jelly, the graphite does enhance temperatures over just petroleum jelly alone (which is a rather awful thermal paste by itself.
Soft pencils are perfect for this - they contain a lower ratio of clay to graphite - and are perfect for powdering easily. A mortar and pestle is great for this; one can break a pencil in half, lengthwise, extract the "lead" (a linguistic artifact from a time when lead was used for marking objects), and powder it through a variety of means.
Then, mix with petroleum jelly to obtain the consistency, and slight grittiness, of regular thermal paste. Apply in slightly smaller quantities than typical pastes - the petroleum jelly does lose viscosity with temperature more so than an OEM paste.
Dust, after water, is perhaps the greatest nemesis of electronics - it causes overheating, it causes shorts, it causes all manners of trouble for the sensitive circuitry contained within every modern device. One of the best means of removing said dust is, of course, through air pressure; nonetheless, there come occasions, when electric compressors, or even, canned air, are unaffordable luxuries. For this very reason, a substitute must
I found two options to be highly useful - one, a plastic bottle with a hole through the lid - or, more conveniently, a small, rubber enema bulb. The greatest advantage of the enema bulb over the platic bottle, is that unlike the latter, it self-inflates. Unfortunately, the bottle cap must be removed, and the bottle, "re-formed" once air runs out.
Of course, neither is a substitute for a proper compressor; still, the enema bulb in partiuclar, delivers the exact sort of pressure necessary to blow out stubborn dust bunnies.
In my time as a tech, I've found that broken plastic is as troublesome as a shorted circuit, a blown capacitor, or a destroyed trace. Many modern electronics use plastics as crucial mounting pints for circuitry, daughter boards, and other bits - most recently, I'd encountered a laptop, where the charging port was friction-mounted, only via two fragile plastic tabs. One of the tabs, having broken off, rendered the chrging prt hopelessly lost within the entrails of th machine.
Upon opening, I'd discovered that an entire corner of the laptop's hard, platic shell, had broken off, with significant pieces missing. My only option was, to re-make the piece. As I'm not a big fan of plastic welding - and I wasn't able to find suitable pieces anyways - I used tape to mold a "form" of sorts, into which I'd poured baking soda - the addition of extra-thin CA glue (regular superglue), created an exothermic reaction, where the baking soda became a sort of solid "substrate", suspended by the CA glue.
NOTE - please work in a very well-ventilated space, and keep your eyes away - the fumes are highly irritating to the respiratory tract, mucous membranes, and eyes.
Now, in this category, I will include some adhesives, which are used in atypical fashion - my favorite, and one I try to crry on me whenever possible, is a glue stick and a cigarette lighter. Contrary to popular belief, there is little need to use a full glue gun for the purpose of melting hot glue - sufficiently heating it with a lighter will render it hot enough to be "globbed" onto anything you need, to make a semi-permanent mount.
Starches, gelatins, and other organic substances, can make fantastic adhesives - particularly when used in applications over large surfce areas.
Broken traces on circuit boards can oftentimes be repaired, quite easily, I must add, by simply using a jumper wire over th broken section - if one scrapes off the shielding over the board, to expose the bare copper below and above the break, a jumper, harnessed from a piece of broken hardware, can serve as a fantastic substitute.
Upon soldering the jumper into place, make sure to isolate it, by dabbing on a bit of epoxy, hot glue, or other insulating material.
In absolutely crucial, field-repair conditions, jumpers can be harvested from an unused fan, cheap headphones, or even unused SATA cables - particularly on a modular power supply. Attempt at your own risk.
WHen a multimeter is unavailable, most circuit voltages can be read with jumpers, and an LED with a resistor. Both fit into a matchbox - alongside that nub of hot glue you're surely carrying, and tiny tube of CA glue.
As much of the circuitry ranges from delivering ~1.5 to ~5 volts, try with a resistor first, and if you get nothing, try without a resistor - you c even hook up two jumpers to the positive lead, such as to be able to quickly check variable voltages. You can even use the two jumpers as a sort of voltmeter, to determine if it's a low or high voltage line.
An interesting phenomenon that I'd observed since arriving here, is that most households don't have the same sheer volume of computrs that can be found in the typical Canadian home. Many households, really, only hve the one machine.
For this reason, do not expect for your friends / clients / customers to have a spare USB key, or a computer from which you can download drivers, or make a quick boot disk.
Always carry a full boot image on a portable USB, and a second, install USB with Windows 10. Most people are perfectly happy with it, and installing Windows 11, for someone that's unfamilir with the system, especially the older users, is very inconvenient.
For this reason, I always have a portable Ubuntu boot disk, to conduct diagnostics, and a Windows 10 install disk, in case something goes wrong.