Please check your firmware version on your device first before upgrading your device, 

If your DSL-3785 is with firmware version AU_1.00, please upgrade your device by following the steps, 

Step 1	 please first upgrade your device with "DSL-3785_AU_20180528.bin"
Step 2	After step one, please then upgrade your device with "DSL-3785_AU_20180528_c.bin"
Step 3	Lastly, please upgrade your device to "DSL-3785-AU_1.03.bin", a Factory Restore is recommended after the firmware is successfully upgraded


If your DSL-3785 is with firmware version AU_1.01/ 1.02/ 1.03, please upgrade your device directly with "DSL-3785-AU_1.03.bin", a Factory Restore is recommended after the firmware is successfully upgraded
