Bought second hand goodmans DGB3 fre...

You must mean the GDB3, Goodmans never made anything called a DGB3.

There's nothing you can do Tony, you've bought a dud.

The GDB3 sold new for under £15 in many outlets and I bought two of them for £10 each; at that price it's not designed to be repaired and failures when under warranty are just binned and replaced by the retailer/manufacturer. Even a replacement remote control costs more than the box originally cost.

You've been unlucky and bought unwisely on this occasion, but don't let it put you off Goodmans in general as they're generally more reliable than many others at the same price level. Don't buy another used Freeview box though as there are many which are out of date and incompatible with the latest Freeview technical standards. You can still buy new boxes for under £20 if you shop around.