Today I have been on my PD3v4 to do a flight using the B737-800 with the default panel but for some reason the radio stck is blenk in the 2D and 3D panels I have searched everywher but cant find a fix, any help would be apprciated. Thanks

Default or addon 737-800?

In Prepar3D (P3D) v4, a blank radio screen on the 737-800 is a common issue often related to power management, corrupted files, or add-on conflicts. The specific fix depends on which 737-800 you are using, such as the default P3D aircraft or an add-on like the PMDG 737 NGXu. 

For all 737-800 models

Power management: The most frequent cause is a lack of power. Ensure the battery and avionics switches are turned on. If starting from a cold and dark state, follow the proper power-up procedure. Some users have found that a blank radio indicates that power was cut to the set.

Restart the simulator: Sometimes, the issue is a temporary licensing or loading error. A simple restart of Prepar3D can resolve the problem.

Remove shaders: Corrupted shader files can cause display issues. Deleting the shader folder forces the simulator to rebuild it.

Navigate to C:\Users\[Your User Name]\AppData\Local\Lockheed Martin\Prepar3D v4.

Delete the Shaders folder.

Quartz font issue: An outdated or corrupted quartz.ttf font file can prevent radio displays from rendering correctly.

Copy the quartz.ttf file from [Your P3D installation folder]\Fonts.

Go to C:\Windows\Fonts, find the existing quartz font, and delete it.

Paste the quartz.ttf file you copied and choose "Install" when prompted.

Restart your computer. 

Thank you for the reply it's the deafult 737-800 panel (no stack showing in the 747-400 and 777-200) I have tried the above with no sucess. The stack in 2D is just a black box.