If your phone starts doing weird things, like turning off by itself, sounding bad, or losing coverageIt's most likely not a simple software glitch, but rather a faulty physical component. The good news is that you don't need to be a tech expert to have a pretty good idea of ​​which part might be causing the problem in an Android smartphone.
With the right tools, you can Check the health of your phone's hardwareWe'll check the battery, screen, sensors, connectivity, and cameras, and even generate comprehensive reports that are very useful if you're going to buy or sell a used phone. Let's take a look, calmly and step by step, at all the reliable ways to detect what's wrong with your Android device using built-in tests, hidden codes, and specialized apps.
Signs that a component of your mobile phone is failing
Before you start testing like crazy, it's a good idea to look at the clues that your phone is already giving youCertain symptoms are almost always associated with specific components, and can give you a lot of guidance before moving on to more advanced tests.
When the The battery takes ages to charge, and it discharges way too quickly. If the percentage drops in erratically, the prime suspect is the battery module itself or the charging circuit. In other cases, the problem might originate from the USB connector or even the charger, but the discharge pattern usually indicates internal battery faults.
If you notice that the The speaker distorts, sounds very quiet, or makes strange noisesThe problem is usually with the main speaker or the earpiece. The microphone might also be faulty if the other person hears you choppy or not at all when you're on the phone.
An The screen darkens for no reason, flickers, or doesn't respond well to touch. This points to problems with the LCD panel, the touch digitizer, or the light sensor. If there are also areas where your finger doesn't respond, the digitizer is probably damaged.
When the The keyboard gets locked, the phone rotates on its own Or if the compass is pointing in nonsensical directions, that's where sensors like the accelerometer, gyroscope, or internal compass come into play. And if the GPS places you on the other side of town, there could also be a problem with the positioning module or the antenna.
Check the health of your hardware with diagnostic apps
A very convenient way to find out what's happening with your mobile phone is to use hardware diagnostic applicationsThese tools are responsible for testing each component of the phone one by one and generating a fairly comprehensive report with the results.
These apps can review in detail screen, sound, sensors, camera malfunctionsconnectivity, battery and processorAmong other things. Many even generate a report that you can save as a PDF or HTML file, which is very useful if you want to demonstrate the actual condition of a mobile phone you are going to sell or check a used phone you are about to buy.
TestM: guided and highly visual analysis
One of the most complete and easy-to-use apps is TestM, available on Google Play and for other systems. With TestM you can analyze the main components of your Android smartphone through a series of guided tests that are not complicated.
When you install it from the Google store, the app will ask you permissions to access virtually all elements of the mobile phoneThis is normal, as it needs to test sound, cameras, sensors, connectivity, etc. You accept the permissions, it installs, and the first time you open it, it shows you a short tour across several screens with the typical Next button until you reach the message that everything is ready.
On the main screen you will see six large circles representing groups of componentsScreen, Sound, Motion, Connectivity, Hardware, and Camera. As you complete tests in each category, these circles fill up, and when everything is correct, a green symbol appears indicating that that part of the phone is healthy.
From that screen you can choose between a Rapid test or a full testThe quick test focuses on the essentials for a basic check, but if you really want to know what hardware is failing, it's recommended to run the full test, which includes around twenty short tests.
In each test, the app shows you a screen with Very simple instructions: touch areas of the screenYou'll need to press physical buttons, speak into the microphone, place your hand near the proximity sensor, activate Bluetooth, check the flash, and so on. Once you're ready, press Start and follow the prompts. If you're not interested in a particular test or can't complete it, you can skip it by pressing a Skip button.
Within each category, you can see a list of available tests and repeat any of them as many times as you like. A button is also included for... verify the entire group of components at onceWhen you complete all the tests and all six circles are filled and green, you will have a very accurate picture of your phone's condition.
Other useful features of TestM
In addition to the tests, TestM includes a side menu that you can access tapping the menu icon in the top left cornerIt shows the exact model of your phone, the number of tests performed, and a number of additional options.
From that menu you can access a section of advanced device informationIt includes information about available storage, screen resolution and type, camera specifications, processor, and even the IMEI. This IMEI code helps you check if a phone has been reported stolen or if it's unlocked to connect to networks in different countries.
TestM also offers detailed battery information, internet speed testsThe option to send feedback to the developers or create a complete record with the results of all the tests. And, if something went wrong during testing, there's a section called Find Repair Shops that shows them on a map. nearby workshops where you can take your phone.
Other testing apps: Phone Doctor Plus and Phone Check
There are other alternatives on Google Play that also work for detect which component is failing in your Android phoneTwo of the best known are Phone Doctor Plus and Phone Check, both free and with versions also for other systems.
Phone Doctor Plus is able to check around thirty different elements of the deviceIt checks the touchscreen, battery, memory, compass, microphone, speakers, flash, Bluetooth, and cameras, among other things. If, for example, you can't open a webpage, the app itself can tell you if the problem is with the network connection, Wi-Fi, or mobile data.
Phone Check, for its part, is designed to offer a A very comprehensive guided analysis of the phoneIt checks memory, storage, battery, mobile networks, Wi-Fi, and many other components. If everything is in order, it displays a green checkmark; if it detects any faults, the result appears in red so you know something is wrong.
Both apps generate clear reports, and in the case of Phone Check, you can send you the report by email to save it or share it with a technical service or with a potential buyer if you are going to sell the mobile phone.
Advanced diagnostics with Device Info HW
If you want to go a step further and find out in detail every piece of hardware that makes up your phoneOne very interesting app is Device Info HW. It's not a typical interactive test, but rather a tool that attempts to identify and display as much information as possible about the device's hardware and software.
Device Info HW attempts to detect components such as screen, touch digitizer, cameras, sensors, RAM memory, eMMC or UFS memory chipsaudio chip, NFC, charger, Wi-Fi and batteryprovided the system allows reading that data. In many modern models, some information is restricted, but the app extracts everything it can.
From its tabbed interface, you can see very detailed SoC dataCPU model, number of cores and clusters, processor family, ABI type, governor, maximum and minimum frequencies, as well as the GPU model, manufacturer, OpenGL version and list of supported extensions.
You also have complete information about the system and the installed ROM: Android version, build number, security patchesThe memory section displays the type of RAM (e.g., LPDDR) and, in some devices, even the operating frequency of that memory. It also shows RAM and internal storage usage.
The battery section displays basic data such as level, temperature and status, and many phones also include download speed, upload speed, and consumption profile defined by the manufacturer. It can even display a kernel profile and model to better understand how the device manages power.
Device Info HW includes extra sections to view temperatures by thermal sensor, List of sensors with tests to verify their operationInformation on installed apps (including system apps), driver list, storage partitions, voltage regulators (PMICs), Wi-Fi connection details, and Bluetooth capabilities.
The app offers a feature of creation of reports in HTML or PDF In its paid version, it's very useful for sending data by email or saving it for reference. And if you have root access, you can read even more low-level information, which is especially useful for developers or those who create custom ROMs and kernels.
Integrated diagnostics in Android: hidden codes and special menus
Android hides a internal diagnostic menu that is activated with special codes from the Phone app. It's a little-known but incredibly useful feature because it allows you to run hardware tests without installing anything and without needing root access.
These codes vary depending on the manufacturer and, in some cases, even between models of the same brand. The idea is simple: you open the phone app as if you were going to dial a number and enter a specific combination of symbols and numbers. When you finish, instead of making a call, A hidden menu opens with tests for screen, keyboard, sensors, battery, Wi-Fi and other elements.
Most common diagnostic codes by brand
The codes most frequently used on Android phones to access these test menus are the following, which you must enter no spaces on the scoreboard:
- Samsung: *#0*# to open a panel with tests of screen, sensors, colors, vibration, etc.
- Xiaomi, Redmi and POCO: *#*#64844#*#* or access the CIT menu from settings for hardware testing.
- Sony: *#*#7378423#*#* to open your internal testing service.
- HTC: *#*#3424#*#* to run guided terminal tests.
- Huawei: *#*#2846579#*#* to enter the device's testing menu.
- Motorola: ##4636## or, in recent models, its own diagnostic help app.
Upon entering the correct code, the phone displays a List of components with their own testScreen, keyboard, touchscreen, battery, Wi-Fi, Bluetooth, sensors, camera, speaker, microphone, and more. You can tap each one to see how the device responds in that specific area.
The advantage of these menus is that the whole process is Integrated by the manufacturer itself and you don't depend on third-party appsIn addition, many brands use these tests in official technical services to ensure that the hardware is working as it should after a repair.
However, it should be noted that in some countries or with certain operators, The codes may be deactivated or do nothing.In those cases, you can always resort to the diagnostic applications mentioned earlier, which offer a very similar experience.
Brand-specific diagnostic tools
Some manufacturers go beyond the codes and offer apps or proprietary tools for performing diagnoses on their Android phones. This is especially useful when you're checking a second-hand phone or want to rule out hardware faults yourself.
On Samsung Galaxy phones, for example, the code *#0*# usually opens a Test menu with buttons to check screen, sensors, vibrationcameras and other elements. If the code doesn't work, it may be because the operator has disabled that function to use their own support software.
Modern Motorola phones have a pre-installed app called Device Help (or something similar). From there, you can access the section... Device diagnostics and running battery and audio testscamera, connectivity, and touchscreen. Within the same application, there is a hardware diagnostic option that includes sensors such as proximity sensors and cameras, and a complete test of the entire device.
On Google Pixel phones, access to diagnostics may vary depending on the model. In some cases, the same method can be attempted. code *#0*# on the dialerAnd if that doesn't work, Google offers self-help flows through its online community. There you can describe the problem, enter your email address and the device's IMEI to follow a troubleshooting guide.
Huawei phones include a built-in app called HwMMITest that acts as a diagnostic tool. It doesn't appear as a regular app; you have to go to Settings, then to Applications, and enable the option to show all system apps. search for HwMMITest to be able to run itTo perform the guided hardware test, the battery should be between approximately 55% and 80%, and some models require booting into a special boot mode.
Professional diagnostic software and certification of used mobile phones
Beyond the average user, there are diagnostic suites designed for second-hand shops, technical services and telephone wholesalersThis type of software looks for more than just a simple "everything is fine": it offers complete certification reports for each device.
One of the clearest uses is when Buys a second-hand Android phoneJust as you wouldn't buy a used car without checking its history, you shouldn't pay for a mobile phone without a clear picture of its condition. Without a thorough check, you risk acquiring a stolen device, one with non-original parts, or one with serious hardware defects.
Professional diagnostic software performs similar tests to those we've seen (audio, battery, cameras, screen, sensors, and connectivity), but adds features such as verification of the authenticity of key components: cameras, LCD panel, battery, fingerprint button, or motherboard. This way it detects if non-OEM replacement parts have been installed.
When we talk about OEM (Original Equipment Manufacturer), we are referring to parts manufactured by the same manufacturer that designed the deviceUsing non-OEM parts can lower the cost of repairs, but it often means lower quality, worse results, and, in many cases, the loss of the warranty. For a buyer, knowing whether a phone has non-original parts is essential to assessing whether the price is fair.
These diagnostic solutions always generate a written report with all resultswhich can be saved in the cloud, exported to PDF and even printed as a label to stick on the box or on the phone itself, showing that the device has been checked and is ready to use.
The advantages are clear for sellers: by having a Reliable certification that the phone is fully functional, restored, and unlockedIt's easier to build trust, justify the price, and avoid returns. For the buyer, having access to the device's history (brand, model, IMEI, whether it's been reported stolen, outstanding debts, carrier locks, warranties, and previous repairs) is the safest way to avoid unpleasant surprises.
In this professional environment, power is also highly valued. Erase all data from your phone in a certified and secure mannerensuring that the previous owner's information has been completely removed before resale. Some systems have specific secure erasure certifications to offer this added peace of mind.
Practical tips for interpreting the results and deciding what to do
After passing tests with apps or hidden menus, it's time to interpret what the diagnosis tells youAn isolated fault doesn't always mean the phone needs to be thrown away, but it is useful to know when it's worth repairing and when it's better to change phones.
If the tests indicate faults in relatively simple elements, such as speaker, microphone, charging connector or batteryThe repair is usually affordable and quite common in most technical services. In many cases, these components can be replaced without affecting the rest of the hardware.
Conversely, if the diagnosis points to problems in the motherboard, in several critical sensors or in the memory controllerThings get complicated. This type of damage is usually expensive to repair, and the phone isn't always restored to 100% functionality, so sometimes it's more worthwhile to spend that money on a new device.
When diagnostic tests make it clear that the The touchscreen or LCD panel is damaged.Cost must also be considered. For mid-range or high-end phones with complex screens, original replacement parts can be very expensive. However, if the rest of the hardware is in perfect condition, it can be worth the investment.
If you intend to sell your mobile phone, having a clean diagnostic report allows you to to demonstrate to the buyer that the hardware has been checked and is in good conditionAnd if the report reveals flaws, you can be transparent, adjust the price, and avoid potential claims later on.
Having all these tools—apps like TestM, Phone Doctor Plus, Phone Check, utilities like Device Info HW, hidden menus by code, and professional diagnostic solutions—allows you Go from simple suspicions to having concrete data about which hardware is failing in your Android smartphoneWith that information in hand, deciding whether to repair, change your mobile phone, or negotiate a fair price for a used device stops being a lottery and becomes an informed decision.
