Disco 4 (LR4) Gps signal discovery 4 2012

Hi , I have a discovery 4 and have lost the gps signal . Got the box on the nav screen with the red lin through it . I’ve had it into the garage and had a brand new roof antenna fitted but still not solved the problem.
Has anybody had this problem and sorted it ? , searched for hours for an answer but can’t find anyone that has actually sorted it .
Any help or suggestions would be greatly appreciated, thanks .

HI, did you run the self diagnostic on it?
"With the touchscreen at the Home page, touch and hold the screen top centre for 5 seconds, then to the same top left for five seconds - until the keypad appears. Enter the code 753 "

Just tried the 753 thing but my car dose not accept that code. Mine seems to need a 4 digit code . When I look on YouTube about the code you suggested ,it appears to be for an older model 05-09 plates. My car is a 2012 model , don’t suppose you have a different code do you ?.
Thank you for taking the time out to reply .

Maddog1980 said:

Just tried the 753 thing but my car dose not accept that code. Mine seems to need a 4 digit code . When I look on YouTube about the code you suggested ,it appears to be for an older model 05-09 plates. My car is a 2012 model , don’t suppose you have a different code do you ?.
Thank you for taking the time out to reply .

Click to expand...

Something is wrong then cos this is from the LR4 2012 diag protocol as you can see in the pic.... you might need a firmware update or to replace the touchscreen as it's stated in the diag doc in the WSM