The problem with the expected product images

[krawcu86_k]

In the store there is a strange problem with displaying the product image, i.e. after clicking on the image, the popup window will not be opened but will open as a new window. An example in an appendix store is on Magento 1.9.3.9 Please, give me a hint where to look for a solution. Thank you in advance for your help.

[Agarwal Aman]

Are you talking about product detail page images? If yes 

Check app/design/frontend/{package}/{theme}/template/catalog/product/view/media.phtml.
If your theme is somehow similar with the default one you should find something like this:

<a href="#" onclick="popWin('<?php echo $this->getGalleryUrl($_image) ?>', 'gallery', 'width=300,height=300,left=0,top=0,location=no,status=yes,scrollbars=yes,resizable=yes'); return false;" title="<?php echo $this->htmlEscape($_image->getLabel()) ?>"><img src="<?php echo $this->helper('catalog/image')->init($this->getProduct(), 'thumbnail', $_image->getFile())->resize(56); ?>" width="56" height="56" alt="<?php echo $this->htmlEscape($_image->getLabel()) ?>" /></a>

Focus on the popWin. That one opens the image in a new page.
Remove this link and insert your logic for zoom in the same file.

If you want to use default Magento pop-up you can use windows.js

This link will help to implement pop-up 

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