If a DUI checkpoint is not properly advertised does the case get dismissed?

I don't practice in Ohio, but I have lived in states where DUI checkpoints are used. I have never heard of a requirement that checkpoints be advertised. Sometimes police will issue a statement warning of their intent to use the checkpoint, but the whole idea behind them is to stop drivers who are impaired. People who try to avoid checkpoints after spotting them routinely get stopped. So, no, I don't think a "failure to advertise" buys you a dismissal.

It is required in Ohio that the location be publicized. Typically it is on the local news and then there are signs/notifications set up in front of it. It doesn't mean the case will be automatically dismissed, but it certainly gives you a possible defense to beat the charge.

In states where DUI checkpoints, better called "ROADBLOCKS," the laws and procedures of "advance" notice roadblocks vary. Whether or not the government's failure to provide advance notice of any particular roadblock will result in a dismissal (my thinking would be, "no") depends upon a number of factors. Go over all of the relevant facts, confidentially, with an experienced DUI defense attorney in Ohio.

You should really contact an attorney that deals with DUI/OVI matters in Ohio for assistance. Lett the attorney see the facts and they can explain the situation to you. Remember, police often do saturation patrols around checkpoints.