You’ve bought your first custom mechanical keyboard kit, and now you need to know if the PCB works before pouring in hours of work only to find out that the PCB was broken.
In this step-by-step guide, we go over all of the steps and materials needed to test your keyboard PCB to see if it’s working before you build your own custom.
1. Metal Tweezers
First, you’ll need a pair of metal tweezers. The reason they have to be metal is that you are essentially completing the circuit of each switch (or at least where the switch pins go), telling the keyboard to register it.
If you don’t have access to a pair of tweezers, it is possible to do this with a paper clip that you DIY to be the distance between the two pads on your PCB. All you need for this is a pair of pliers and a paper clip.
Of course, to test a PCB, you need a PCB. Make sure that you handle your PCB gently and do not damage any of its electrical components.
3. Compatible USB Cable
You’ll also need a method to connect your PCB to your computer. This is done through a USB cable.
Check with your PCB to determine whether you need a USB-C, Mini-USB, or Micro-USB cable. For convenience, we use an interchangeable cable that can connect to all three.
4. Switch Testing Software
For switch testing, we prefer to use either Switch Hitter or VIA (if your PCB is compatible).
Switch Hitter can be downloaded here, and then it can be used many times on your PC just by opening it.
VIA is also a downloadable program. However, not all PCBs are compatible with VIA. You can download VIA here, as well as check for compatible PCBs.
If your PCB is, then definitely download it. It’s a much easier interface to work with and has a ton of features like remapping keys, layers, and more.
For a full list of recommended tools that we use, see our custom keyboard cheat sheet here.
How to Test Your PCB
1. Clean Your Surface
Before you open up your PCB’s packaging, make sure you have a clean workspace that is clear of any static electricity.
Similar to working with computer parts, you won’t an environment that won’t potentially damage your PCB.
Personally, I work on a cloth desk mat and clean the surface beforehand.
Despite what people say, your PCB is actually a lot more durable than you might think. But with that in mind, treat it well because it’ll last a long time.
Now you may take your PCB out of its packaging.
2. Connect Your PCB to PC
When you’re ready and have your workspace set up, now it’s time to connect your PCB to your computer using the compatible cable.
If your PCB has RGB lights, you’ll see the lights glow. If your PCB has an LED light signaling that power is running through it, you’ll see that as well.
It really depends on what PCB you have, even ones without RGB lighting will have a method to tell you that it’s turned on.
3. Open Your Switch Testing Software
Now, open up Switch Hitter or VIA, whichever one that you decided to get.
VIA, if it recognizes your PCB, has a test matrix that you can open up that will show you the layout of your PCB. You can also opt to turn on sounds. That way, when you test it, it makes sounds rather than having to look at the screen to know that a key works.
For example, if you have a 65% board, it’ll show you that layout. It also gives you the option to split spacebar, split backspace, etc.
If you’re using Switch Hitter, it only shows the tenkeyless and full-sized layouts, but you can also test 65%, 1800-compact, 75%, and other layouts with it as well.
4. Test Each Individual Switch
Now get your pair of tweezers, and for every switch placement (with two pads) on the PCB, you’ll connect one end to one pad and the other end to another.
On your software, you’ll see the key light up and then turn into another color, indicating that it works.
If you test a switch and see nothing happening, you can try again with different positioning slightly.
If it still doesn’t work, then most likely, that key on the PCB is not working properly.
Continue down each row and column, testing each switch one-by-one.
For certain PCBs with different bottom row layout options, you’ll see that there are many pads side-by-side.
I test all of the keys, but it’s optional if it’s not a layout you ever plan on using.
5. Next Steps to Building a Custom Keyboard
Now that you know your PCB works, what are the next steps to finishing your custom mechanical keyboard?
We have a full step-by-step guide for how to build a custom keyboard from start to finish if you’re interested in reading more.
Do I Need To Test the PCB?
When you first get a PCB shipped to you, it is recommended that you test it before doing anything else.
You don’t want to be in a position where you’ve soldered everything on only to realize that a key doesn’t work. Then it’s hard to diagnose whether it’s the switch, the PCB, or a poor solder job that is the cause of the problem.
What is a Keyboard PCB?
PCB stands for printed circuit board. The PCB is what sends signals to your computer that you pressed a certain key.
There are different kinds of PCBs that are available for you to purchase.
The PCB is pretty much the brain of the whole operation, so make sure you get one that you like.
The first thing to think about when choosing a PCB is what kind? Do you want a through-hole design? A soldered design? Or hot-swappable so you don’t have to solder at all?
A through-hole PCB doesn’t have many of the parts required to make it work soldered on. For example, you’ll have to solder the diodes, resistors, fuses, reset buttons, LED lights, the microcontroller, and USB port for it to become a functioning PCB.
Usually, through-hole PCBs are not recommended for beginners because they require a lot of effort. Also, they can be quite frustrating if something doesn’t work and you don’t know why.
However, a through-hole build is a great weekend project if you’re wanting to show off your impressive soldering skills or build something that’s a bit different.
A solderable PCB is probably the most common one that you’ll see. This PCB only requires that you solder in the switches.
This PCB is recommended for builders of all skill levels. Standard PCBs allow you to have more flexibility in terms of layouts and key placements.
For example, some standard PCBs allow you to choose between ISO and ANSI, split backspace, split spacebar, and split shift. Alongside that, there are many different bottom row layouts that you can pick from.
A hot-swappable PCB already comes with hot-swappable sockets soldered into it.
This PCB is most recommended for beginners because it requires no soldering at all unless a socket gets pulled out.
With these PCBs, all you need to do are install the stabilizers, and push in each individual switch. After that, it’ll work great.
No soldering is required.
What Do I Do If It Doesn’t Work?
If you’re in the testing phase and you see that your PCB doesn’t work, be sure to contact the vendor or supplier of the PCB as soon as possible.
It may still be in the period where you can return the PCB for a replacement or a refund.
If you wait too long before testing, then the vendor or supplier has the right to turn down your return/refund/replacement request, simply because having the PCB sit in your home too long may have caused it to not work.
In conclusion, testing your PCB should be done as soon as you receive it in the mail. Alongside this, you want to make sure it’s done before you start building your keyboard.
If you do forget to test it, then be sure to test it before your solder in your switches. That way, you’ll at least save time if any trouble arises.
It’s also a really easy process that can be done very quickly with little equipment or none at all.
Hope this guide helps you, and good luck with building your first mechanical keyboard!
- PCB not recognized/disconnects in use.
- Switch not registering.
- Hotswap specific.
- Hotswap and solderable.
- LED Issues. LEDs won't turn on, or keyboard disconnects when LEDs turned on. Underglow/LED does not change until keyboard is reset. Only some of the LEDs are working.
The first way to test a laptop keyboard is to open any word processor such as Microsoft Word, Google Docs, or other and begin typing all keys one by one. If all keys register well, your keyboard is fully functional.
The Windows on-screen keyboard is a program included in Windows that shows an on-screen keyboard to test modifier keys and other special keys. For example, when pressing the Alt , Ctrl , or Shift key, the On-Screen Keyboard highlights the keys as pressed.
- In-circuit testing.
- Flying probe testing.
- Automated optical inspection (AOI)
- Burn-in testing.
- X-Ray inspection.
- Functional testing.
- Other functional testing (solderability, contamination, and more)
As long as the PCB is disconnected from power and left for long enough for the capacitors to discharge, you shouldn't have a problem as long as you ground yourself first.
Can scratching a PCB damage it? Yes. You can damage the copper tracts that carry the current.
Darkening of the skin or nails may also occur. PCB exposure may also cause abnormal liver tests or an enlarged liver in some individuals. PCBs can cause reproductive and hormonal effects, and, in exposed children, developmental, immunological and neurological effects.
- Trapped dust and debris. ...
- Moisture in the air. ...
- Physical damage and liquid spills. ...
- Neglect – laptop unused for an extended amount of time. ...
- Keys not working. ...
- Keys repeat itself. ...
- Keys come out with a different output. ...
- Keys are jammed, or stuck.
Test keyboard without laptop battery
A good test is to completely shut down the device, remove the battery if possible, connect the external power supply, and reboot. If the keyboard works without issues, then the battery may have issues supplying a steady current and need a replacement provided by the OEM.
When your keyboard fails to work, it could be due to:
- Physical damage.
- Filter keys.
- Outdated or corrupt driver.
- Low battery (if you're using an external keyboard).
The F3 key is a function key found at the top of almost all computer keyboards. The key is often used to open the find or search feature of a program or operating system. As mentioned below, F3 also has other uses depending on the computer and program. How to use the F3 key.
- Unplug the keyboard and plug it back in. ...
- Try a different cable. ...
- Replace the batteries. ...
- Clean the keyboard. ...
- Blow out the unresponsive switch. ...
- Use contact cleaner. ...
- Inspect the solder joints. ...
- Replace the switch.
The Fn key, short form for function, is a modifier key on many keyboards, especially on laptops, used in a compact layout to combine keys which are usually kept separate.
To test circuit board properly, touch the multimeter probes to the test points present on the board. Make sure while playing out this step you have your hands on the plastic portion of the probes. You can then go on to check either the voltage or resistance.
- Key Takeaways. Learn the signs of a short circuit. ...
- Visually Scan the PCB. ...
- Look for Signs of Burnt Components. ...
- Probe with a Multimeter. ...
- Use a Thermal Camera. ...
- Destructive Testing.
The simplest form of PCB inspection is manual visual inspection (MVI). To perform this type of test, a worker looks over the board either with the naked eye or through magnification. They'll compare the board to the design documents to ensure that all specifications were met. They'll also look for common defaults.
Magnets and electronics do not get along. Strong electromagnets can damage electronic components by stripping away the device's programming, thereby rendering it useless.
In particular, polycarbonate electronic components, typically in PCBs, seals and gaskets, are extremely harmed by exposure to an isopropyl alcohol cleaning solution.
PCBs, or polychlorinated biphenyls, are industrial products or chemicals. PCB chemicals were banned in the U.S. in 1979 because these chemicals harm human and environmental health.
Hot glue is fine, the stuff's wonderfully non-conductive. I've repaired a monitor flyback with it before... Just be careful hot-gluing electrolytic capacitors - they don't particularly like high temperatures.
Environmental Factors: Exposure to heat, dust and moisture, accidental impact (drops and falls), and power overloads/surges can be causes of circuit board failure. However, the most damaging cause of premature circuit board failure is electrostatic discharge (ESD) at the assembly stage.
The presence of moisture can lead to various functional failures on a PCB, depending on which components or conductive paths come into contact with it as diffusion takes hold.
- Disturbed Joint. A disturbed joint typically occurs as a result of movement while the alloy is solidifying. ...
- Solder-Starved Joint. A solder-starved joint is just that: a joint that does not have enough solder. ...
- Untrimmed Leads. ...
- Cold Solder Joint. ...
- Solder Bridge.
While you need to make sure your soldering iron is hot enough to melt the solder, you want to avoid overheating your solder at all costs. This can cause severe damage to your PCB, the other components and even your soldering iron tip.
Circuit Board Testing Methods for Rigid PCBs
The most common method to check PCB construction quality is visual inspection, which is typically performed throughout the PCB manufacturing process.
The coplanar PCBs, known as nonortho PCBs because they are not substituted at the ring positions ortho to (next to) the other ring, (such as PCBs 77, 126 and 169), tend to have dioxin-like properties, and generally are among the most toxic congeners.
While not a direct factor in what causes PCBs to burn, improper conformal coatings can negatively affect your PCBs. If dust or other particles make their way near already-hot components, they could ignite.
ISO is the reccomended cleaner, acetone is to aggresive and can damage components, it is never used in industry to clean PCB's.
The life expectancy of a computer keyboard depends on a number of factors, with brand name mechanical keyboards lasting 10 – 30 years whereas a cheaper membrane/rubber dome keyboard might only last 2 years in total.
Mechanical keyboards can last for up to 10 years or more depending on how heavily they are used. Mechanical keyboard switches are rated for 50+ million keystrokes, which will last for years of heavy use.
- Spill Something. ...
- Forget to Clean. ...
- Clean Incorrectly. ...
- Rage Smash. ...
- Transport Incorrectly.
These clicking sounds are caused by Filter keys that make keyboard operations easier. These sounds and typing delays caused by Filter Keys can become very troublesome.
Using Only a Mouse
Select "Device Manager" from the pane on the left. Expand the Keyboards section, right-click on the keyboard you want to repair and choose "Uninstall." Click the Windows "Start" button and select "Restart." When your computer boots up, Windows will detect your keyboard and install the driver.
Unlikely that the keyboard could cause any damage. The keyboard is entirely powered from the USB port, so there are no voltages higher than the port can handle. And the USB specs are such that you can short anything to anything inside (or beyond) the USB cable without damaging the computer.
When a keyboard stops working randomly, it's usually a connection or software issue. Check all physical connections for any dirt or broken parts. Also, test the wireless connection to ensure it's not cutting out. Updating the keyboard driver is a common and easy software fix to a glitching keyboard.
The function keys or F-keys on a computer keyboard, labeled F1 through F12, are keys that have a special function defined by the operating system, or by a currently running program. They may be combined with the Alt or Ctrl keys.
Ctrl + F12 opens Word document.
Ctrl+F8: Performs the Size command when a workbook is not maximized. Alt+F8: Displays the Macro dialog box to create, run, edit, or delete a macro. F9: Calculates all worksheets in all open workbooks. Shift+F9: Calculates the active worksheet.
- Unplug your keyboard.
- With the keyboard unplugged, hold down the ESC key.
- While holding down the ESC key, plug the keyboard back into your computer.
- After about 5 seconds, release the ESC key. You will see the keyboard lighting flash if the reset is successful.
F10: Starts the spell checking program in the active document, if the document's program has this feature. Shows or hides the Office task pane that was previously displayed. (This is not available on all keyboards.)
- The F1 key.
- The F2 key.
- The F3 key.
- The F4 key.
- The F5 key.
- The F6 key.
- The F7 key.
- The F8 key.
The function keys or F keys are lined across the top of the keyboard and labeled F1 through F12. These keys act as shortcuts, performing certain functions, like saving files, printing data, or refreshing a page.
- Turn off any power to the circuit before examining the board. ...
- Check the circuit board for fuses. ...
- Examine components on the board for signs of physical damage. ...
- Turn the digital multimeter on and set it to its diode test function.
- Tools Needed Before Troubleshooting Your PCB. Table of Contents. ...
- Inspect Visual Elements. ...
- Inspect Physical Components. ...
- Test Individual Components. ...
- Test Integrated Circuits. ...
- Inspect The Power Supply. ...
- Compare a Defective Circuit Board With a Good One. ...
- Signal Probing.
In general, yes. A regular keyboard matrix made out of mechanical switches can be cut: it is electrically the same as if the keys are never pressed. I and several others have done that to some inexpensive vintage keyboards, making tenkeyless or smaller keyboards out of full-size keyboards.
Luckily, it's possible to repair or remanufacture boards to make them like new again. This does one of two things. Either the board in question can be returned to its original device, making it function again. Or, it can be used in a completely different device, as a form of recycling if you will.
- Step 1: Tidy Up the Damaged Track 1: ...
- Step 2: Tidy Up the Damaged Track 2: ...
- Step 3: Exposing the Track: ...
- Step 4: Sticking Copper Tape Over the Exposed Track: ...
- Step 5: Soldering the Copper Tape Joints: ...
- Step 6: Pierce to Make the Hole: ...
- Step 7: Solder in Your Component:
Electromagnetic compatibility (EMC) and electromagnetic interference (EMI) are two issues that are common on PCBs.
Every single key on a mechanical keyboard has its own independent switch mounted underneath. This allows for each key to have its own feel and response when pressed. The switches have an incredibly long lifespan. You're looking at 50-100 million keystrokes before the switch will even think about breaking.
If water or any other liquid gets inside the device, it can reach the circuit boards and cause the device to stop working. Cleaning the board can sometimes restore functionality once the board is dry.