I have a replicator port (VGA only) that goes with my Dell Laptop. I also have one Dell monitor (VGA) and a second Dell monitor with both VGA and DVI. The replicator port only has one VGA port. I can create a dual screen using the laptop screen and either monitor, but when I try to go dual monitors (laptop screen closed), nothing shows up on the VGA monitor. Is it possible to use both types of monitors?
Without knowing the specifics it is hard to say.
My dual monitor at home is connected to the replicator dock. First is VGA cable and second is via DVI cable with the laptop screen closed. The home set up is tricky as it involves the replicator connecting to the VGA port and one of the DVI ports. If both your monitors are DVI, the process is much easier.
1) Try different cable combinations. VGA has only one possibility, but DVI could be placed into port 1 or 2. In between combinations, make sure to fully close the laptop screen and shut down the laptop each time you try a different combination.
2) Replace the VGA monitor with one that supports DVI.
Why you can not use a VGA to DVI cable.
You can not use VGA to DVI cable converter since the replicator dock only accepts DVI-D (DVI digital).