I opened the box and booted the PVR up with the HDD disconnected and still received the same error message on the box. I can hear the HDD spinning up when it was plugged in so at point I can only conclude that it's main board issue.
This thread is regarding the 4250. The 4250 is not a PVR. I'm assuming you either have an 8642 or a 9865 since you mention a HDD.
It's strange that it did not boot. Even if the HDD failed, most will function as a set top box without recording capability. Did you have Rogers check the signal to your box and/or to your neighbourhood? Could they "see" the box and report the signal? Did you reconnect the HDD?
Let us know if the rental works at the same location. If the underlying issue is signal-related, the rental may work for a while and then fail in a short while.
Do you have another box in your home that is working? If so, you could swap the boxes to help troubleshoot. If the problem stays with the box, then the box is likely the problem, although some boxes require more signal than others to function properly. If the problem stays with the "location" then the signal is the likely problem.