To test a campaign, the first check you should do is to review the campaign itself and its settings to ensure the campaign is live.
Then check the banners in this campaign to ensure images are being displayed (critical if using 3rd part tags) If banners are not being displayed then please speak to whoever provided the tags to check they are live.
A further test you can do is to test the tags, linked to zones in both a .html file and also if you have the facility and a developer who can help, on a live webpage.
To do this, link your campaign to the zones you wish to test.
Then extract the invocation codes from the ad units to the campaign you wish to test.
With the invocation code file you have downloaded, please open this .txt file
Then go to File – Save As and save it as test.html as shown below:
Then close this file, locate it where you saved it and open within a browser and you should see the ads linked to these zones open up as a dummy .HTML file.
An alternate way to do this would be to pull the invocation codes as above, then get your web developer to put these live on a test page so you can check delivery on a live page.