IP Helper-Address DHCP

Good Evening

I am having an issue with configuring my Powerconnect 6224 switches to forward DHCP requests from one VLAN to another.

Here is what I have:

• (4) Powerconnect 6224, 1 acts as Gateway and other 3 are acting as L2 switches
• Switches are link through Stacking cable in Unstacked mode
• Have 3 VLANs, 1-3
  • VLAN1: 192.168.70.251/24
  • VLAN2: 192.168.73.251/23
  • VLAN3: 192.168.75.251/23
• DHCP server (192.168.70.7/24) is attached to gateway switch on vlan 1
• PC is on another switch
• All switches have firmware 3.3.1.10

Any help would be great!

Thanks
Ed