Your models are really very simple constructions, thus very easy to re-construct in SH3D.
Select a model, like the Data Server Tower. Export it as an obj-file.
Choose a box, import it to your project, and select modify.
Apply the same dimensions to the box, as the dimensions of the Data Server Tower, and select Modify.
Apply a grey colour ( or whatever colour you prefer) to everything but the front and the back, and then select front. Click on texture, and select import. Find the image file that was exported with your model, and apply it to the front. Then do the same with the back. Make sure to set all shininess to zero.
Select OK.
Do the same for the PDU, and voila: Your models will now render just fine.
I have already done it for you: PDU+ServerTower
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