Getting regular 'Internal server error - 500" pages

Can anyone suggest what I ask my host to do to find out what the heck is going on with their servers. Every few days we get the page 'Internal server error - 500' and the local error logs for the domain shows nothing. The host claims the server is 'working fine' !

The scripts are all working ok as far as I can see, and have been working like so about 3 years without many changes apart from minor word changes to some files.

Is there some logger or something that they can use to find out anything as to why this error is showing up ?

Most of the time those errors are caused by files or folders with the wrong CHMOD settings. Your hosting company should have checked them first, though. And if you haven't made any changes then the permissions seem like a long shot.

Hey thank you for your reply, I have checked the CHMOD of all files and all seems fine. The file had not been changed in what 6 months or more, and I already uploaded the whole site again after checking everything anyway and still we get these errors.

It is not just this site, it is all of them that I have under my account with them. They say the usual please check your files are correctly coded and what-not but why would they work one day and not the next when no changes have been made. I even tried to grab the files from the server after backing up my end first and checking the files, a few hours later, I can not see any changes that have been made to any of the files.

Still baffled.