GX270 Status Lights A,B,C,D?

Dell Users,

Can someone please send me a link that tells me what the status lights on the back of the GX270 refer to? I'm trying to trouble shoot one that has an amber B light, but I can't find a reference chart the tells me where to look next. Getting no video out of it right now. This one doesn't appear to the the bulging capicator issue, like so many other of our GX270s :smileyvery-happy:

Thanks,