PDF English version of this manual.

The goal of this manual is to present the various steps involved in refurbishing computer hardware, and CPUs in particular.

This manual lists the refurbishing methods used by the Emmabuntüs collective.


Equipment survey

Before reconditioning computer equipment, there’s a very important step: finding it, either by searching through your personal network, or following the proposal to donate equipment.

This is the most important stage, because it will determine the amount of work you’ll have to do to restore the equipment to its original condition, as well as the time you’ll have to spend on the logistics of taking it to the scrap yard, donating the computers or even storing them if you can’t give them away or sell them quickly.

The first question to ask yourself before taking the equipment on, is to know how to dispatch it. If you don’t know how to distribute the equipment, there’s no point in taking it on, because you’ll end up paying for its management and storage instead of the donor 😉

External visual inspection

Once you’ve identified who you intend to use the equipment for, and who will accept it, you need to ask yourself whether the computer equipment you’ve been offered or found is worth reconditioning. In other words, will it be suitable for the people who need it ?

Before telling you what equipment you should take, we’ll explain what equipment you shouldn’t take, and you can easily guess its state by asking what operating system the computer comes with, or looking at simple photos of the equipment, as there are also color modes for computer equipment 😉

Here after a perfect example of a computer and its peripherals that you absolutely must not take unless you want to start running a computer museum 🙂


Computosaurus : even Linux can’t do anything for it
except installing an obsolete Linux version !


Criteria for non-acceptance


Operating systems prior to Windows 7, e.g. 95, 98, NT, XP, Vista

A computer with insufficient RAM, hard disk and processor resources to run a Linux version that is still being maintained.

‍Incomplete CPU or laptop, e.g. no RAM, hard disk or video card

This will require a study to find the missing parts and additional costs, so be vigilant about this.

Raspberry Pi

A Raspberry Pi is not like a regular computer, it’s more resources limited, requires a particular Linux version and also an SD card that may not be present. So there’s a lot of work involved in getting it up and running. In fact, it’s aimed more at electronics enthusiasts.

White colored central unit

Since about year 2000, all CPUs have been colored in black, so this equipment was manufactured before and is therefore too old.

Cathode-ray tube or CRT

Screen too large and, above all, with too low a resolution

Ball mouse

Too much maintenance and no longer manufactured

Keyboard or mouse with PS2 port

No longer manufactured since 1998, and recent computers no longer implement these ports.

‍Wireless keyboard or mouse

Often you don’t have the wireless transmitter that goes with it 😉 Also more fragile than the wired model, and expensive because of the batteries.

Device with parallel port

These parallel ports are no longer implemented on recent computers and have been massively replaced by USB ports.

Ink-jet printer

If the printer has not been used for some time, the ink will have dried and clogged the nozzles.

‍Expansion boards of all kinds

These boards have been used within a specific machine, and we need to know which one so that we can reuse them again.


Note : If, at the end of the analysis, you find that a “Computosaurus” may be of interest to a collector, a retrocomputing and vintage hardware enthusiast, try to give it to him/her, as it’s better to keep this equipment than to take it to the garbage dump, and it’ll also make someone happy. If you can’t find anyone to give it to, you can also try to sell it on eBay (or equivalent) with the words ‘vintage computer, and it should sell quickly 😉

The ideal equipment for re-use that we recommend is a complete computer, 6 to 8 years old, max. 12 years, with a flat screen from 18 to 22 inches. It should have a hard disk with a minimum capacity of 120 GB, 4 GB RAM and an Intel Core i3 or higher processor. It is of course possible to use weaker configurations such as an Intel Core 2, and 2 GB RAM, but this means that the computer will be slower and, above all, will be between 12 and 17 years old, which implies that this machine will no longer have a long life expectancy. The best of the best being a laptop 🙂


© QW83 / Wikimedia Commons, CC-by-4.0

Interior visual inspection

Before starting to work on a central processing unit or any other piece of IT equipment, it is essential to carry out a visual inspection before powering up the equipment. For CPUs, we recommend that you open the case, and make a visual inspection to see if all internal components are present: hard disk, memory sticks, processor chip with its cooling system, and make sure that no metal elements such as PCI slot covers are lying around in the case.

In the case of a laptop, it’s important to ensure that the various hatches at the rear of the case have not been opened, as can be seen from the state of the screws. If these have been opened, you need to reopen them to see if the internal component under the trapdoor is still present.

Note : A visual inspection can also be made of all the chemical capacitors on the motherboard, to check that none of them are leaking. This problem is characterized by the top of the capacitor bulging, or worse, by traces of rust, which will eventually lead to computer operating problems. We advise you to not use motherboards with this kind of problem, even if they can be repaired, because this will add a long job of dismantling the motherboard and replacing all the capacitors.

Chemical capacitors in good condition
© Giovanna 27 / Wikimedia Commons, CC-by-4.0


Before taking the computer and its motherboard to the scrap yard, remember to remove the hard disk, memory sticks, power supply unit, fans and possibly the processor, which in fact is more difficult to change as it is very specific for each motherboard.

Note: If the computer has additional extension cards other than the graphics card, or several hard disks, it is preferable to remove these and leave only one hard disk, if you think that this additional hardware is not necessary for the end user. This avoids software driver implementation problems for these expansion cards, and reduces the power consumption.

First start-up

This initial start-up will enable you to assess the computer’s functional state, for example, to see if it boots correctly on the old operating system. If it boots correctly, simply switch it off, then go on to the next step to install a new operating system.

If it does not start up correctly, there are several possible scenarios:

  • If an internal component is missing, you’ll have to replace it with an equivalent one, which is why it’s a good idea, when a motherboard is potentially defective, to recover the components that are still working on it;

  • The computer displays the BIOS or UEFI screen, in which case it’s highly likely that the so-called CMOS battery is discharged. In this case, simply switch off the computer and unplug it from the mains (2 safeguards are better than one!), then replace the battery with a new one, often a CR2032 type button cell. Then, in the BIOS or UEFI menu, you’ll need to update the computer’s date and save it, then reboot (see further explanation here);

  • The computer displays nothing, or emits several beeps. In this case, it’s highly likely that one of the computer’s components is not working properly, or that there’s a faulty contact. To try to fix this, switch off the computer and unplug it from the mains (2 safeties are better than one!), then remove each of the memory sticks and wipe them out with a tissue before putting them back in their slots.


Example of RAM sticks in a CPU
© Cyberdex / Wikimedia Commons, Domaine Public


If it takes you more than 5 minutes trying to find a solution to this boot-up problem, we advise you to put this computer aside and put a label on it describing the problem in a few words, and then treat another computer. The aim is to recondition functional computers first, then to treat non-functional or faulty computers afterwards.

Installing a new operating system

When refurbishing a computer, it’s best to install a new operating system, particularly Linux, to give the computer a second youth and save time on computer maintenance compared with cleaning up the old operating system.

Operating system installation

To install Linux on the computer, there are two possible options: either you use the installer supplied with the distribution, or you first make a clone of the Linux distribution in question and then use the Emmabuntüs refurbishing flash drive (or re-use key), which has been designed precisely for this purpose. The advantage of the cloning method is that it saves time of installation on the new system, and the clone itself can be customized. We consider that beyond the reconditioning of 5 computers, the cloning method is the most efficient, even taking into account the time needed to make the clone.

Note : Whatever method you use to install Linux, we recommend using a USB memory stick instead of a DVD, as this is the fastest and safest technique, providing you use a memory stick is of good quality. See the USB 3.x sticks we use on this page.

Note : Of course, not all USB sticks are equivalent in terms of speed, but also in terms of being well supported by the computer boot function. To minimize problems, we advise you to use brand-name flash drives and avoid small size USB flash drives.

Note : For the fastest possible installation, we recommend using the USB ports on the rear panel of your computer, with priority given to USB connectors with blue coding and USB flash drives with blue coding also, which indicates that the equipment in question is in the USB 3.x format. See the various symbols next to the USB ports on this Wikipedia page to describe them.


USB ports in USB 3.x format
© Amin / Wikimedia Commons, CC-by-4.0


Note : Before proceeding with the installation, we advise you to disable the Secure Boot (see how to do this here) as well as the UEFI options, in order to have better support by the computer for Linux operating systems. Try also to use a single clone for the reconditioning of your computers, otherwise you’ll need several clones: a Legacy, a UEFI and/or a Secure Boot. See the various Emmabuntüs clones available on this page.

So to install the new Linux system, we recommend the following tutorials, depending on the method you wish to use:

Testing the new operating system

Once the new operating system is installed, it is necessary to perform the following checks:

  • Run the “Disks” tool (known as gnome-disk-utility), to check the status of the hard disk using SMART data. If this data indicates a future hard disk failure, you will need to replace it;

Disks utility

SMART data from the Disks utility

  • Run a music playback utility, such as Clementine, to check the system audio outputs

Playing a piece of music in the Clementine utility

  • Launch an Internet browser to check Ethernet and WiFi connections, if present on this computer;

  • Insert a DVD into the DVD drive to check that it is working properly. This is not necessarily required if you think the DVD will not be used by future users;

  • Let the computer run for at least 30 minutes, ideally an hour, to detect any potential overheating of some components.

Note : If, when using your computer, you notice problems with software shutdowns or operating system crashes, we recommend you test the RAM using the MemTest86+ utility, which is included in the toolbox of our refurbisking key, for example. We don’t recommend systematic RAM testing, as this can be very time-consuming and ultimately fail to detect any RAM faults.

Note : If you’re using a clone that we call FreeCulture, we recommend that after the cloning operation, you install an offline version of Wikipedia, available here, and pair it with the Kiwix application. First copy your file with the .zim extension into the /FreeCulture/Wikipedia folder, then when the copy is complete, open Kiwix, then click on “Open file” as shown in the image below to select the Kiwix file to be imported into the application:


Warning : If you are using a new version of a .zim file, we advise you to test it before deploying it on several computers, as there may have been a problem in extracting the Wikipedia database to generate this file, or when downloading it.

Checking the screen display

To test the correct operation of a screen, we recommend that you install the ScreenTest software, available here, on one or more computers to set up screen test stations, which should be left running for at least half an hour, or even longer, to see if the screen functions correctly when it is hot.

This utility lets you see the screen’s defects by switching from one mode to another by clicking on the middle mouse button, or by clicking on the right mouse button to bring up the software’s various options, such as the “LCD Alignment” function, which lets you see if the screen is flickering:

Screentest utility with option menu displayed via a mouse right-click

Testing printer operation

In the context of hardware reconditioning, we don’t encourage the re-use of printers, particularly ink-jet printers, as their lifespan has been deliberately limited by the manufacturers, and if the printer has been switched off for too long, the ink has dried out at the nozzles.

Laser printers, on the other hand, are of better quality and don’t have the problem of ink drying. So, to see if the printer is working properly, switch it on, then search in its menu for how to print a test page and run a diagnostic to get the printer’s status.

Equipment cleaning

We advise you to clean the equipment in the last stage of the reconditioning process, because there’s no point in cleaning the equipment if it turns out that during the computer reconditioning phase we won’t be able to get it back into working order.

Internal cleaning

To clean a CPU, we recommend using an electric PC blower, or failing that, a hand-held hair dryer with cold air mode. Do not use a leaf blower, which is too bulky and certainly too powerful 😉

Note : We recommend that you dust your computer outdoors, or by opening the windows in the equipment room, and that you wear a surgical mask.

Note : When using the PC electric blower, remember to blow air through the openings in the power supply unit and onto the front of the CPU.

Note : We don’t recommend the use of air cans to clean the inside of computers, as this is very expensive to use if more than three computers have to be cleaned, and it’s also an ecological aberration for people wishing to make re-use 😉

Note : For laptops, we encourage you to change the thermal paste on the processor and its cooling system, as this equipment is very sensitive to heat due to its miniaturization. This type of maintenance is for very meticulous and patient people.

External cleaning

After removing the dust from the computer, it’s time to think about removing any labels the donor has put on his equipment. For paper labels, we recommend soaking them in water to remove the paper part, then using white spirit and wearing gloves to remove the glue. We also recommend doing this outside, or opening the windows in the technical room, and wearing a surgical mask.

After removing the labels, it may be a good idea to clean the external surface of the CPU first with a dry cloth to remove dust, and then with a damp cloth and a little washing-up liquid if necessary.

Note : The keyboard is one of the peripherals that often gets dirtiest, so we advise you to replace it if you see that when using a wipe you won’t be able to clean it.