Fix Computer Not Starting After Installing New Graphics Card

Most modern-day gaming PCs are made of a combination of components that are purchased separately and then put together. Graphics cards are the most expensive part of any system.

Something like a brand of the GPU doesn’t necessarily matter much as long as the manufacturer is well known. However, what matters is the compatibility of the GPU with the system (modern GPUs are not compatible with a very old system with AGP slots for instance).

Several reasons may contribute to computer not starting after installing new graphics card. These include faulty/dirty PCIe slots, bad power cables, an outdated BIOS, wrong video settings in the BIOS, etc.

Chances are that if the graphics card and the motherboard are both in working condition and there is no compatibility issue, you will get everything working by the end of this article.

So How to Fix Computer Not Starting After Installing New Graphics Card

Almost all issues (except for physical damage or dead on arrival) are solvable. The problem can range from motherboard’s BIOS issues all the way to graphics card not inserted properly or the 6-pin or the 8-pin PCIe cables not connected in place (if required by the card).

The issue is most probably being caused by one of many issues, but it’s better if you follow along,

1. Dirty/Faulty PCIe Slot:

If your PC has been running on integrated graphics for a while, it may have accumulated some dirt in the PCIe slot. The primary x16 PCIe slot is where the card is supposed to be inserted and is usually just under the CPU, perpendicular to the RAM slots.

PCIe slots labelled
The blue x16 slots are the longest ones found on commercial products. The first PCIe x16 slot (the top one) is occupied with a graphics card. The smaller X1 cards are for low powered cards like network cards.

To clean the x16 slot, follow these steps:

  1. Turn off the PC & remove all power cables.
  2. Clean the PCIe slot with compressed air or a blower. (Blow into the PCIe slot with your mouth if you do not have an air compressor or a blower)
  3. Take a soft brush and a bottle of Isopropyl Alcohol (IPA).
  4. Wet the brush with the IPA (not too much).
  5. Now rub the brush inside the PCIe slot properly.
  6. Let the PCIe slot dry for a few seconds.
  7. Plug the card back into the slot

If you don’t have IPA, do not use water or any other cleaning liquid, a regular dry brush should suffice. But if you want to be thorough, you should consider buying any form of IPA.

Also, compressed air is not a must; it’s only used to clear out the slot of residues like dust, silicon or carbon flakes.

If you see any damage to the PCIe slot, i.e., it is bent, the pins are coming out, the slot itself has detached from the motherboard, or there is hard carbon on the pins, you should contact your motherboard manufacturer and not attempt to repair it yourself.

If the cleaning processor does not work, move onto the next method.

2. Make Sure the Graphics Card is Plugged Into the Right PCIe Slot

It goes without saying that not all PCIe x16 slots are the same. Some PCIe slots have a physical size of an x16 slot, but can be hardwired to only 4 PCIe lanes.

Most graphics cards require atleast 8 PCIe lanes to work.

does it matter which pcie slot I use w
PCIe Slots for adding expansion cards. Note that the bottom x16 slot actually only has 4 lanes. You can figure this out by reading the specsheet of the motherboard.

If you have a motherboard similar to the configuration as the one above, plugging the graphics card in the bottom x16 slot (which only has 4 lanes) will render it inoperable. 

As such, you will get no display from the graphics card. Your PC will work, but there will be no display.

3. Insert the Card in the PCIe Slot Properly

You may not have simply inserted the graphics card correctly in the PCIe slot, which, if true, means that the card is not connected to the motherboard.

What you need to do is carefully remove the GPU from its slot and insert it back in. While inserting, make sure the graphics card is aligned with the slot. You will see a small cut in the gold strip of the card and a small bump in the slot. Use this for alignment before applying pressure.

When you are sure of the alignment, apply gentle pressure down on the card until you hear a click sound. This click means that the card is now correctly inserted into the slot.  

What does PCIe Clip Look Like
When you plug graphics card into the PCIe slot’s latch properly, it will make a clicking slot.

After this, you will have to place screws on the back I/O panel of the case to hold the card correctly. The screws are essential as leaving the card hanging in the PCIe slot (tower cases) can potentially damage the slot as well as the connectors of the card. Make sure you have suitable screws in place.

Move on to the next step when you are sure that the card is in the right and secure.

4. Make Sure All Power Connectors are Connected

Most GPUs nowadays have high power requirement (more than 100 Watts). These cards require a direct power input from the PSU; without the power cables, the card will not run.

To check whether your graphics card requires additional power, check for the 6 or 8-pin connectors on the top side of the GPU. The connector should look like this:

computer not starting after installing new graphics card
This image shows a graphics card with 2 x 6 Pin Slots.

You need to make sure that ALL the power connectors are connected with the PCIe cables coming from the PSU. 

If your graphics card has these slots and you have not connected any wires, here are the steps you should follow:

  1. Take off the back panel of the casing
  2. Among the PSU cables, look for a wire with a 6 or 8-pin head (they sometimes come with PCI-E written on them)
  3. Insert these heads into the connectors on the GPU (there is a 6-pin head and an additional 2-pin head with it. If the GPU has an 8-pin connector, insert the 6-pin head and the 2-pin head such that they make an 8-pin head)
    Note: If the GPU has two separate connectors, look for two leads coming from the PSU and insert both
  4. Once you have inserted the pins, close the back panel.
  5. Now, connect the power cable to the PSU and turn on the PC

The issue should now be solved. However, if the problem persists or your graphics card does not require additional power, move on to the next step.

graphics card connected
A graphics card that requires 2 x 6 Pin PCIe Power Cables.

5. Weak PSU

One of the biggest mistakes that beginners make is that they do not calculate the GPU and CPU wattage requirement beforehand. Gaming PCs generally require a high and stable amount of power for every component to function.

To see whether your PSU is enough for your system, check the total output of the PSU. Typically, this information is written on the PSU’s body in Watts. After this step, search online for the TDP of your graphics card. Most websites will also tell you what PSU best suits the job.

RTX 3080 power requirement connector
NVIDIA RTX 3080 Power Requirement and Connectors Required. High End GPU such as this require as much as 850W. Source; ASUS

If your PSU is outputting less wattage than the GPU and CPU’s combined requirement, you need to upgrade your PSU to a higher output one.

If this does not solve the issue, or your PSU’s output is balanced with the system’s requirement, go to the next step.

6. Faulty Wires and Monitor Settings

There are many types of ports and wires that are used nowadays. These include HDMI, DP, DVI, VGA, etc.

Now, these wires come with the monitor and connect the monitor to the graphics card’s display output. It would be best if you ensured the wire was working and not faulty. The only way to do that is to use another wire for the connection.

Some monitors do not have an automatic detection feature. If there is still no display with the new wire, ensure the monitor is on the correct mode. For example, the monitor should be on HDMI mode if you are using an HDMI port for connection.

Should You Connect Monitor to GPU or Motherboard
Use the GPU, not the motherboard for monitor.

Also, ensure the wire is connected to the graphics card’s port and not the port on the motherboard. The port on the motherboard is used for integrated graphics cards and not external GPUs.

Also Read: Computer Turns On But No Display – 27 Fixes and Causes

If the issue is still there, go to the next step.

7. You May Require a BIOS Update

The stock BIOS of the motherboard may be outdated, which may cause the motherboard not to recognize the new graphics card.

The remedy for this is simple but should be performed by an experienced individual (you can brick the motherboard if you don’t know what you are doing).

Motherboard manufacturers provide BIOS update utilities, but if there are not available, a BIOS flash is the only method to update.

Note: Proceed with caution. If you have not done this before, it is better to consult an expert. An bad BIOS update can brick your motherboard

Follow these steps to update the BIOS:

  1. Remove the new graphics card from the system.
  2. Find out your motherboard’s number and model (this is important)
  3. On another system or laptop, go to your motherboard manufacturer’s website.
  4. Search for your specific motherboard in the downloads section.
  5. Download the latest BIOS from the website.
  6. Extract the ZIP file and copy the BIOS folder onto a USB drive
  7. Now, boot up your system and enter your BIOS
  8. Navigate to the flash option. (Different for all motherboards. Get help from the internet if you have trouble finding this)
  9. When asked about the drive that contains the new BIOS, select the USB.
  10. Select the BIOS file that you copied.
  11. The system will automatically start updating the BIOS


Once the update is done, the system will reboot. Shut down the system, and install the graphics card correctly.

If the system does not boot up, move to the next step.

8. Check the Graphics Card; Perhaps its DOA

If any of the steps above do not solve the problem, you should check your graphics card for issues.

If it is a new graphics card, then chances are that it may have come Dead on Arrival (DOA).

Therefore, to verify if an issue lies with your graphics card or not, insert the card into another PC (One with different specifications). If it works, then the problem does not lie with the graphics card but with your system.

Also Read: How to Check if Motherboard is Dead?

If the graphics card does not work in another system either then it would be best to contact your graphics card manufacturer for assistance if there is no display on that system.

Note: Do not perform any repairs on a card as this may void the card’s warranty. 

Also Read: Why Does My PC Randomly Turn Off?

Final Words

If you are suffering from the issue of computer not starting after installing new graphics card then there can be many reasons ranging from issues as simple as card not installed properly all the way to the card coming dead on arrival.

If your computer is not turning on AT ALL after installing the graphics card, the issue could be power related, particularly if your PC works without the graphics card installed.

If the GPU is drawing too much power, it would render the entire PC inoperable.

Categories GPU
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Atif Qazi
Atif Qazi is the founder of PCGuide101 and an expert in the computer peripheral industry with over two decades of experience. He has worked as a consultant for major companies and has a deep understanding of the inner workings of computer peripherals. He has a degree in Electrical Engineering and has served as a product manager and technical consultant. He is passionate about testing and evaluating the latest products to provide readers with reliable information.

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