I picked up several 15" Dell E153FPF monitors from a company that was going out of business, as well as an E170S. I've tried both models on my Quadra 840AV with one of those adapters that has the dip switches, and nothing seems to work. I've gone thru the gamut of settings on the dip switches (it has the switch settings printed on the back).

Anyone have any luck getting these screens to work on old Macs?