Internal Screen Fix Guide

Pink Parsnip Computers support guide

AIO LCD screens, case displays and other internal screens can go blank, flicker or stop showing up in Windows. Most of these faults come from how Windows handles the USB 2 connection inside your PC, and most can be fixed in software. Work through the four steps below in order.

Internal screens usually talk to the PC through a USB 2 header on the motherboard. Many boards do not have enough of them, so builds end up using splitter cables. Windows can then fail to recognise the screen, or two drivers can clash, and the screen goes blank. Software fixes sort most of this out. They cannot repair a hardware fault, and the last section shows you how to spot one.

Written from more than 400 PC builds in the last 12 months and the support queries that followed.

Step 1

Update the screen software and firmware

  1. Open the control software that came with your screen or cooler. Brands we see most often include Thermalright, Jungle Leopard and Lian Li.
  2. Check inside the software for an update. If you have never updated it, there is a good chance a newer release is waiting.
  3. For Lian Li, open L Connect and find the device. If it appears, check that its firmware is on the latest version. L Connect has a guide built in that walks you through the firmware update.
  4. When every piece of software and firmware is up to date, shut the PC down completely and start it again.

Why it helps

It sounds too simple to matter, yet many people never do it. Old software and firmware are a common reason a screen drops out or goes blank.

Screen still blank or not detected? Move on to step 2.

Step 2Fixes most cases

Remove stuck USB entries and drain the power

  1. Right click the Start button and open Device Manager.
  2. Expand the USB sections and look for any device with a yellow exclamation mark. That means Windows cannot recognise it.
  3. Right click each affected device and choose Uninstall device.
  4. Check that your screen software is on the latest version, as in step 1.
  5. Shut the PC down.
  6. Switch the power supply off at the back of the PC.
  7. Hold the power button down for about 10 seconds. This drains the power left inside the system.
  8. Switch the power supply back on and start the PC.

Why it helps

The power drain forces Windows to treat the screen on the USB 2 header as a brand new device, so it installs the correct driver from scratch. In our experience this works nine times out of ten.

The rule to remember

Windows can pick up a USB device without recognising it. Whenever that happens, uninstall that device in Device Manager and repeat the power drain from this step.

Step 3

Change the power settings

  1. Set your Windows power plan to performance mode. On Windows 11 go to Settings, System, Power & battery and set Power mode to Best performance. On Windows 10 choose High performance in Power Options.
  2. Open Device Manager and expand the USB sections.
  3. For each USB device, right click it and open Properties. If the device has a Power Management tab, untick Allow the computer to turn off this device to save power.
  4. Repeat this for every USB device that offers the option, including the USB Root Hub entries.
  5. Restart the PC and check whether the screen is recognised.

Why it helps

Windows can switch USB devices off to save power and then fail to wake them properly. Turning that option off stops the screen being put to sleep and lost.

Same rule as step 2

If Windows picks up the screen but does not recognise it, uninstall that device and repeat the power drain.

Step 4

Change the port and replug the screen

  1. Lian Li wireless receiver. Move the receiver to a USB 3 port on the back of the motherboard instead of a USB 2 port. Always use a motherboard port. We do not recommend the USB ports on the case.
  2. Screens or coolers with a plug in connection on the screen itself. Unplug the connector and plug it back in while the PC is on. Take great care not to touch any other component. If you are not comfortable working inside a running PC, skip this one.

Why it helps

A different port, or a fresh connection while Windows is running, can make Windows see the screen as a new device and install its driver properly.

Inside the USB 2 header

Most internal screens plug into a 9 pin USB 2 header on the motherboard. One header carries two USB 2 ports, and many boards have only one or two headers in total. The case front panel usually takes one of them, which is why screens end up sharing.

5VDATA NEGDATA POSGNDNCPort BPort A24681013579Pin 9 is left empty on purpose so the plug only fits one way
A standard 9 pin USB 2 header. Port A uses pins 1, 3, 5 and 7. Port B uses pins 2, 4, 6 and 8. Layouts can vary, so check your motherboard manual before you plug anything in.

A passive splitter cable joins several devices onto the same port, so they can interfere with each other and confuse Windows. If you run short of headers, an internal USB hub board gives each device its own connection and is a safer choice than chaining splitters.

More things to try

Restart instead of shutting down, or turn off Fast Startup

With Fast Startup on, a normal shut down keeps part of the Windows session saved, so USB devices may not fully reset. Restarting does reset them. To turn Fast Startup off, open Control Panel, Power Options, Choose what the power buttons do, then Change settings that are currently unavailable, and untick Turn on fast startup.

Clear out hidden and greyed out devices

In Device Manager open the View menu and choose Show hidden devices. Uninstall any greyed out USB entries left behind by your screen from earlier attempts, then do the power drain from step 2.

Turn off USB selective suspend

Open Control Panel, Power Options, Change plan settings, Change advanced power settings, then USB settings. Set USB selective suspend setting to Disabled. This works alongside the Power Management change in step 3.

Update chipset drivers and the BIOS

Install the latest chipset drivers from your motherboard maker's support page and check whether a BIOS update is available. USB handling improves with these updates on many boards.

Run one control program at a time

If you have software from more than one brand installed, such as a cooler app and a case fan app, several programs may try to control USB devices at once and clash. Close the ones you do not need and stop them starting with Windows.

When it is a hardware fault

Software fixes cannot repair a faulty part. Run through these checks before you spend more time chasing a software answer.

  1. Connect the screen straight to a motherboard USB 2 header with no splitter or hub. If it works there, the splitter or hub is the problem.
  2. Try a different header on the board. If the screen works on one header and not the other, suspect the first header or its cable.
  3. Repeat the power drain from step 2 on each new connection.
  4. If you can, test the screen in another PC.

Strong signs of hardware

The screen shows in Device Manager as Unknown USB Device with a device descriptor request failure on every header, even after the power drain, or it stays dead in a second PC. At that point replace the splitter, cable or screen.

Still stuck? Get in touch with Pink Parsnip Computers support. Tell us which steps you have tried, the brand of your screen and what Device Manager shows, and we can point you to the right fix faster.