Any camera that was working with the Amcrest current DVR should work with the newer DVR.. So I am honest and clear, I will admit that I do have a new 5mp camera from Amcrest that don't work with my 7108-AI DVR but does work on my older 8M16-H5 DVR.. While I say it don't work, I should state that it don't work as intended because I can get the camera to work on any of the other formats other than CVI and seeing Audio for that camera only works in CVI that is why i say it don't work.
Yet all my older 960H cameras have no issue working with any of the newer DVRs that I own..
Main down side to older cameras is that you are stuck with them working in only IR mode at night if they are Color and B/W cameras. where newer tech and or other tech that I own I have the ability over OSD to change the cameras to work color at night. My older cameras don't have OSD to make this change.. So at some point you may want to also upgrade cameras. Can do this 1 at a time or a few at a time.. Or you may find that the updated DVR with a 4 pack camera would best suit your needs as they do have a package deal as well.. That package deal has a 2tb HDD, DVR and 4 cameras and you can find that here..
https://amcrest.com/catalog/product/vie ... egory/160/
I would try another HDMI cable or the D-Sub to see if you can get the one you have already setup and working.. Here is another idea? While this does work on my newer dvR/NVR I don't know that it does on my 960H machine at this point, Will have to go test it back in the shed where it is installed at this time. However. Something to try is take a USB Thumb Drive and plug into the DVRs USB port on the back. Reboot the DVR or plug in the dvr. Give it a few minutes or an hour. Remove power and again plug back in to power. Wait another 10 min or an hour. Then remove the Thumb drive and see if there is any data that the DVR is sending to the Drive. Here is one line from the output of my 4216E-AI NVR.. Talking about the Video
<6>[ 1.703416] Linux video capture interface: v2.00
Also don't be alarmed with any errors in the output. There might be things that are not enabled and may error in the Data dump however if there is a Video Error that might be a different story.
Be Safe.