HP 6470 / 8470 Displayport problem

I just installed with the new installer kit (downloaded the latest package creator) the Mojave to my HP 6470 laptop. Everything is working well BUT no DisplayPort...  I can not mirror or connect to TV .... I had a HP 6460 previously that was OK until I could use HD 3000... For the last Mojave the HD 3000 was not enough.... I have sevaral mainboard so, I tried with a 8470 board too. The result is the same: No video signal !   I  already wrote here but there was no any reply... PLEASE help me, because this mirroring is very important for me because I use my laptop for presentations....  
The deatiled data: HP 8470p  / BIOS 68ICF Ver.F.40  / CPU: i7-3720QM / 16 GB RAM / Display: HD+ (1600 x 900)   OSX: 10.14.6.

HELP  PLEASE !!!!!  

THANK YOU! !!!!

Not working on 1600x900
If you find the solution post here the result
thanks

Years ago I installed a hackintosh to a friend of mine with the similar parameters machine (HP8470p with HD+ display) ,   and that is still working with the mirror screen... I tried that EFI and the mirror is working for me too !!!!   BUT!  with this old EFI there is no USB3 .... I wish to send to you that EFI but I dont know how to send files here.   So with this old EFI the  task is how to make left side USB connectors (USB3) working.  Please let me know:
1., how to send EFI zip file ?
2., how to add to this EFI the USB3
THANK YOU !!!

Dear Friends,
Now EVERYTHING is working with HD+ (1600x900) display!!!
If you wish to know how, please let me know how to upload files here. I can share my EFI.zip file .... It seems working on HP 6470b as well as HP 8470p with high resolution displays....

I not need EFI I need How you make it work

Hi, I made a different EFI ... There is no dsdt.aml, and the config.plist is different. the EFI drivers are the same, but the kexts folder also different... Now I just updated/modified an old EFI file. The old EFI is origin by RehabMan I think, - he made it years ago for HP ProBooks.... In this EFI there is no dsdt, but a lot of patches (31 pcs!) in the ACPI section.

Zsolt Szekely a écrit:Hi, I made a different EFI ... There is no dsdt.aml, and the config.plist is different. the EFI drivers are the same, but the kexts folder also different...   Now I just updated/modified an old EFI file. The old EFI is origin by RehabMan I think, - he made it years ago for HP ProBooks....  In this EFI there is no dsdt, but a lot of patches (31 pcs!)  in the ACPI section.

Good Luck

Thank you!
I know this couple of dsdt patches is not very elegant, but I am not able to edit dsdt.... A hackintosh GURU, - like you are - could make it.... That is why I thought to send to you this working EFI.
Anyway, now all functions on Mojave is perfectly works !
If you could have a look this solution you may develop your very good installer program set for HP ProBook/EliteBook...
Have a nice day !!!