Thanks for your question.
What is the display showing when you turn the cash register back on?
Does it appear to function even though the display is blank?
e.g. can you do a No Sale and open the cash drawer?
If so, the display cable may just have come loose coincidentally - a common problem on the TE2400's.
If this is the case, you will need to open it up and reseat the ribbon cable for the display.
Hi, just checking in on your question, do you need any further assistance?