White Screen for admin on one site in multisite

I have one site on a multisite where I cannot access the admin screen. the frontend works fine, and I can access other client's admin accounts as well as the network admin for the site.

I've turned on debug and have it sent to a log file, but I don't see anything there that's not being listed for other accounts, just Notices and one Strict Standards.

I disabled the theme and all the plugins and neither resolved the problem.

Checked the apache error log, but didn't see anything there either.

Any suggestions to get admin access back?