Many users are faced with a situation where the old all-in-one PC is gathering dust in the corner, and the new laptop requires an additional screen to work. A logical question arises: is it possible to use monoblock as an external monitor for a laptop? The answer to this question is not as clear as it seems at first glance, and depends on the specific model of the device and its technical characteristics.
Unlike standard computer monitors, all-in-one computers are full-fledged computers with their own processor, RAM and operating system. It is this feature that creates the main technical confusion: most users mistakenly believe that any screen with a video input is automatically suitable for connecting an external signal source.
The reality is that 90% of the time, directly connecting an HDMI or DisplayPort cable from your laptop to your all-in-one PC won't work. This is due to the fact that video inputs on such devices are often absent, and the existing ports are designed solely for outputting images, and not for receiving them. To avoid wasting time and damaging your equipment, you need to study the technical capabilities of your device in detail.
Technical difference between video input and video output
The main problem lies in the architecture of the video card and ports installed on the monoblock motherboard. In the vast majority of cases, the HDMI or DisplayPort connectors are on the rear panel Apple iMac, HP All-in-One or Dell Inspiron work only as video output. This means that they can transmit an image from an internal computer to an external projector or TV, but cannot receive a signal from the outside.
To use the screen as a monitor, you need a specific video input (HDMI In, DisplayPort In). Such ports are extremely rare and usually only in top-end or specialized models. If there is no marking on the device body In next to the port, it most likely does not support the signal receiving function. Attempting to supply power to the output port may result in a short circuit or damage to the laptop's graphics card.
Some manufacturers such as Lenovo or Acer, in certain series they implemented the function Target Display Mode or similar solutions, but they often required special software or cables. Without clear documentation confirming the presence of the input function, you should not count on a direct connection. It is important to check the specifications on the manufacturer's official website, paying attention to the "Video ports" section.
Specifics of connecting to Apple iMac all-in-one PCs
Company Apple created a unique solution that became an exception to the general rule. Monoblocks iMac (released before 2014) supported the regime Target Display Mode, allowing you to use their screens to display the signal from another Mac. However, this functionality was limited to specific models and generations of processors.
A cable was required to connect Mini DisplayPort or Thunderbolt, and both devices must have a compatible version of macOS installed. It's important to note that this feature did not work with Windows PCs, making the solution virtually useless for most users. After 2014, Apple stopped supporting this feature even for its own devices, making it impossible to use new ones iMac as monitors.
If you have an old one iMac 27 inches with an Intel processor, there are chances, but the setup process requires strict adherence to the sequence of actions. You need to press a keyboard shortcut Cmd + F2 on the keyboard of a connected Mac while in download mode. Without a native keyboard and a compatible operating system, the system simply does not activate the image reception mode.
⚠️ Warning: Never try to use HDMI to Thunderbolt adapters to bypass restrictions, as this does not change the physical nature of the port and may result in hardware failure.
- Yes, successfully
- No, I haven't tried it
- Tried but didn't work
- I'm going to try
Alternative network connection methods
If a physical cable connection is not possible, software solutions using a local network or the Internet come to the rescue. These methods allow you to broadcast an image from a laptop to an all-in-one PC screen with minimal latency if both devices are on the same network. It's not ideal for fast-paced games, but it's great for working with documents and watching videos.
To implement such a scenario, you will need to install special software on both devices. One of the most popular programs is Spacedesk, which turns any network-enabled computer into a second monitor. There are also solutions from Microsoftsuch as function Connection in Windows 10 and 11, running via the Miracast protocol.
- 🖥️ Install the server driver Spacedesk on an all-in-one PC and a client application on a laptop.
- 🌐 Make sure both devices are connected to the same Wi-Fi network or Ethernet cable.
- 🚀 Launch the application and select the candy bar from the list of available displays to expand your desktop.
Signal delay (lag) is the main disadvantage of this method, especially when the network load is high. The quality of the picture will depend on the bandwidth of the router and the speed of the candy bar processor. For comfortable operation, it is recommended to use a wired connection via Ethernet instead of wireless Wi-Fi.
Before using software solutions, close all unnecessary applications on the all-in-one PC to allocate maximum processor power for processing the network video stream.
Using a video capture card as a bridge
The most reliable way to turn any all-in-one computer into a full-fledged monitor is to use video capture cards (Video Capture Card). This is an external or internal device that converts an analog or digital video signal into a format understandable by the computer’s USB port. This method works universally and does not depend on the presence of specific video inputs on the candy bar body.
You will need to purchase an inexpensive capture card with an interface HDMI on USB 3.0. One end of the HDMI cable is connected to the laptop, and the card is inserted into the USB port of the all-in-one PC. The system will recognize the card as a webcam, and the image will appear in any application for viewing the video stream, for example, Observation window or OBS Studio.
Although this method requires additional costs and takes up one USB port, it gives 100% results. The signal delay is minimal and almost invisible to the eye, which allows you to even play undemanding games. Image quality depends on the class of the capture card: cheap models can produce low resolution, while professional devices support 4K and 60 Hz.
It is important to correctly configure the display settings in the operating system of the all-in-one PC. The window with the video stream needs to be maximized to full screen and all unnecessary control panels disabled to create the illusion of a native monitor. Some users even disable the main OS interface on the all-in-one PC, leaving only the video capture window.
☑️Capture map setup
Comparative analysis of connection methods
For clarity, let’s compare the available ways to use a candy bar as a second screen. Each method has its pros and cons that should be considered when choosing a strategy. Direct cable connection is the fastest, but technically difficult or impossible for most devices.
| Method | Required Equipment | Image quality | Signal delay |
|---|---|---|---|
| Direct connection (HDMI In) | All-in-one with HDMI In port | Excellent (native) | Zero |
| Target Display Mode (Apple) | iMac 2009-2014, Macbook | Excellent | Minimum |
| Network software (Spacedesk) | Two PCs, Wi-Fi/LAN | Average (depending on network) | High |
| Video capture card | HDMI-USB card, HDMI cable | Good (depending on the card) | Low |
The choice of method depends on your goals. If you just need to expand your workspace to work with text, a network solution will suffice. However, for working with graphics or a video capture card will become an indispensable tool that ensures stability and clarity of the image. Don't forget that an all-in-one monitor consumes more power than a typical passive monitor, which can be an important factor when working for long periods of time.
Hidden information about capture cards
When choosing a capture card, pay attention to the chipset. Cheap cards with UVC chips can produce strong artifacts and flickering, while models with Realtek or Synaptics chips provide a stable picture without loss of quality.
Limitations and nuances of operation
Even with a successful connection, the all-in-one PC will not be an ideal monitor due to differences in ergonomics and settings. All-in-one PCs often do not have the ability to adjust brightness or contrast through external buttons, since these parameters are controlled by the operating system. This may be inconvenient if you plan to use the device as your main screen for a long time.
The all-in-one operating system continues to run in the background, consuming processor and RAM resources. This can lead to overheating of the device, especially if the cooling system is designed for standard office tasks, and not for constant processing of the video stream. It is necessary to monitor the temperature and ensure good ventilation.
In addition, the screen resolution of the all-in-one PC may not match the optimal resolution of the laptop, which will lead to blurry images or the need to scale the interface. In Windows this can be solved through settings Scale and layout, but on macOS and Linux the process can be more complex. Using an all-in-one computer as a monitor requires a free USB port and stable operation of the operating system on the all-in-one computer itself..
⚠️ Attention: Make sure that automatic system updates and sleep mode are disabled on the candy bar so that the screen does not go dark at the most inopportune moment during operation.
A video capture card is the only universal solution that allows you to use any all-in-one PC as a monitor without the risk of damaging the equipment.
Final recommendations for choosing
Before you begin experiments, carefully evaluate the feasibility of the idea. If the all-in-one PC is old and weak, its use as a monitor may be ineffective due to high requirements on system resources. In this case, it is easier and cheaper to purchase a separate monitor that will work passively and will not require additional power.
If you have a powerful all-in-one PC that's sitting idle, using it as a second screen is a great idea for creating a multitasking workspace. This will save space on your desk and avoid purchasing additional equipment. The main thing is to choose the right connection method based on the technical capabilities of your devices.
Remember that equipment safety must come first. Do not use dubious adapters and do not ignore system warnings. With proper setup and choosing the appropriate method, an old all-in-one can get a second life, becoming an indispensable assistant in work and entertainment.
Ultimately, the decision depends on your willingness to spend time on setup and perhaps a small financial investment in a capture card. For enthusiasts, this is a fun project that allows you to optimize the use of available resources. For those looking for a simple and quick solution, network programs are an excellent compromise.
Is it possible to connect an all-in-one PC to a laptop via USB-C?
Only if both devices support the mode DisplayPort Alt Mode and the monoblock has a port with the function Input. In most cases, USB-C on all-in-one PCs only works as an output or for charging, so a direct connection without a capture card is not possible.
What program is best for using an all-in-one PC as a monitor?
The most popular are Spacedesk (free, works via the network), Deskreen (allows access via browser) and TeamViewer (for remote access). The choice depends on the requirements for latency and picture quality.
Does connecting a laptop to an all-in-one PC via HDMI damage it?
No, it does not damage if both devices are working properly and use standard cables. However, if you connect a cable to a port that is an Output rather than an Input, this can create a signal conflict, although modern devices are usually short-circuit protected.
Is it possible to play games on an all-in-one PC connected as a monitor?
Yes, but with reservations. When using a capture card, the latency is minimal, allowing you to play. When using online solutions (Spacedesk), the latency may be too high for fast-paced shooters, but is fine for strategy games or RPGs.