CntrlAltDel

Hi there, I was recently tasked by a friend to find out why it is he couldnt use two cameras he purchased on his DVR. I noticed that the particular DVR had very little branding with very little emphasis on vendor support so I concluded that the DVR is some generic device he got on the cheap. He has 8 cameras already installed two of which died due to weather damage hence the two replacements. The specific model of those cameras are AHD TD-7524AS. I read some specifications online regarding this particular camera and found that it required you to set the video output to CVBS. The problem is the DVR doesn't have that option so when connecting the cameras you just see a black screen on that channel. I was hoping since it may be a generic DVR with multiple branded models available with similar UI's that actually support that encoding method and physical features that are exactly the same that there'd be a firmware update that could possibly allow for this encoding method from a different brand. So far what I tried was to use the firmware upgrade tool from the dahuawiki website in hopes that it could somehow find a firmware for this model but the DVR for some reason rejects TCP traffic to port 80 for handshake between the upgrade tool and the client PC, even though when configured that way the web UI uses it fine after the necessary network configurations on the router. I even enabled DMZ for the local address the DVR uses to allow all ports but the DVR itself still reject connections. The web streaming of footage from the camera works fine even on port 80 but the moment I try to use the tool it rejects the port 80 requests. The DVR's model number is D6008D-F with the brand only referred to on the packaging as "ET". More information can be found in the images below: