Floating grounds? how do u find them?

[godfreyl]

...guess, made due to lack of information.

+1
It would help a lot if the OP told us something about the circuit - what it is, what it's supposed to do. If he showed us the schematic in question and maybe a photo of the actual module, we might be able to figure out what's going on.

Without any further info though, all anybody can do is guess wildly.

I can actually think of a few reasons why a PCB may appear to have "floating grounds". For example, one of the more annoying things I've come across was a PCB whose ground connections were via the screws holding it to the chassis. Alternatively, the grounds in question may rely on connection to some other piece(s) of equipment. Then again maybe the circuit in question consists of several independent, separately grounded modules on the same PCB. Who knows?

 

[barry]

If the schematic doesn't match the PCB, doesn't that make it "wrong"? SOMETHING is wrong, and the OP is not very forthcoming. His fundamental problem seems to be that his schematic doesn't match his board.