Hi Jerry,
You may or may not remember me. I'm the plumber who was talking to you in the parking lot in Kearny Mesa about jeeps and Detroit lockers.
If the drains are full of dirt sometimes a snake won't clear it.
May require a high pressure jetter to clean it out.
Area drains can often be a real b*tch to clean. They are often neglected for so long and roots can severly impact them.
Many a time I've had to dig up the drains to remove roots.
We use Rigid Equipment
K1500-Sectional-Machinewith 1-1/4" cables and even these bad boys won't grind through pipe full of mud.
PM here or JF. I'll give you some referals to a good drain service
AKA Krazedav @ JF