Grundig Xenaro GDP-3100 region-free hack

Get into the Service Menu. This is not intended for home users, only for service technicians. Therefore you're asked for an access code, it is 8500 for all Xenaro DVD Players

Activate "System Messages" using the Service Menu

Leave the Service Menu and get into the "System Information" Menu

When you see the System Info, enter the following code on the remote control. Note that the player will not print the code on the screen, you have to enter it blindly.

The code for the 3100 is: 70307194

The code for the 3200 is: 70307195

The code for the 4204 is: 70307196

The code for the 5100 is: 70307196

The code for the 5120 is: 70307198

The code for the 6150 is: 70307192

A system message should appear. It will not appear if you got the code wrong or if you did not activate system messages in the service menu. Confirm the message with Ok on the remote

Now a window appears in which you can change your region code. Values 1 to 8 and "none" are possible. "None" will disable the internal check of region codes (i.e. makes the player CodeFree), but RCE titles might not work. This doesn't really matter, as you can change the code as often as you wish to match a specific disc

If you want to, you can disable System Messages again using the Service Menu after you changed the code