Well you definatly need to get your trunk open before you can see whats going on with the top.
you will need to make sure that the partition cover in the trunk is pulled forward and latched into the switch, the soft top will not open if that is not latched.
To open a convertible top for a Mercedes CLK 430 manually, open the trunk. There is a switch located in the trunk if the driver's switch fails. The switch is located in the far reaches of the trunk next to where the top and the trunk meet.
if you cannot open the trunk with the key, remove the rear seat and crawl through to open the trunk from inside.
check the trunk near the battery.
make sure the luggage guard is locked in place in the trunk
I have a CLK 430 convertible and it is a pain. But you will find a positive post under the hood on the drivers side. There should be a plastic cover that flips up. You can jump the car from here or get enough juice to open the trunk by this method. If the trunk does not open turn the key in ignition to power up and then should open.
There should be a button by in the center column area where the window buttons are. Also, if it is an unlocked position you should just be able to push the circle in where you would normally stick the key in. This pops it too!
Open trunk , look inside on left hand set where trunk partioner hook up is engaged , there is a limit switch in it , the first time this happened i stuffed my son in the trunk to pres that button & open the top ! After i just used a bungee cord and shut trunk lid until top opened then i open it take buneggee out & reclose trunk get a new switch installed.
In the trunk.
probably a bad sensor, just take it to the dealer to have it checked
Had same issue for 2001 clk 430. best bet I found was eBay motors and eBay.
next to the spare tire in the trunk.
the battery is in the trunk , it should be fairly simple