I have a ChannelMaster CM-7500GB16 OTA DVR (over the air digital video recorder). It runs on linux (an old Ubuntu version, I believe).

Recently it stopped recognizing my external hard drive, which connects to the DVR by way of a USB 2.0 port. The hard drive, hard drive enclosure, and cable are fine. The ChannelMaster just refuses to recognize that it is there.

How can I perform a hardware test on the USB port in the DVR to see if it failed? It would have to be something that could just plug into the port and test, as you cannot program the DVR in any way.

Thanks for any help.

Moxieman

I take it that the external drive is where the Channel Master unit saves everything it's recorded. If you can read the external drive from another Linux system, what'd try is to duplicate some of the files on the external drive onto a thumbdrive and see if the recognized by the DVR. Unless there's some odd directory structure and/or some metadata that might be hard to duplicate, copying a subset of the external drive onto a thumbdrive might work as a test. Just inserting an empty thumbdrive into the USB port might serve as a useful test, i.e., does the DVR see it as an new storage device? If so, the port's likely not the problem. What would worry me a bit is whether there's a different drive where the DVR keeps metadata about what's on the external drive and, seeing an empty device, figures that data is now obsolete and wipes it.

Also, take a look at Channel Master's support pages. There's this article that discusses something that might be similar to what you're seeing. In that article, there's a link to another page that discusses doing a factory reset. I'm not sure what that entails as you need to be registered on that site to read the details. I'd take a look at it as it might help.

Note: I saw mention on CM's disk drive compatibility list (very short list, BTW) that compatible drives come and go onto the list, some drives may no longer be supported, etc. If CM sends out updates to the unit, I wonder if your current hard disk is no longer supported. If so, you could buy a supported drive, copy the contents from old drive to new drive (retaining ownership and permissions), and use the new drive. Then your DVR is back up and running and you've got a new drive to hang off a PC.

HTH...

Did something happen between then and now?
Is that believed old Ubuntu box connected to the internet?
If nothing changed software-wise, it must be the hardware?

Thanks for the replies.

I did do a factory reset -- no joy, and no, nothing changed before the system stopped working (saving onto the external hard drive). No updates, no nuthin'. The hard drive does work with other computers, but has some glitches, so I replaced the hard drive anyway -- no change with the DVR -- not recognized.

I also checked the ChannelMaster web pages and saw the one you linked to, rnturn. It's for a different device. As I said, I did the factory reset and there was no change. I like the idea of plugging in a usb drive and seeing if it flashes, and then maybe putting a recording on it and seeing if the recording on the USB drive is available.

Thanks.

moxieman

There could be several components that have failed.

host controller or other associated component upstream.
bad power supply voltage to that part of the DVR
broken USB connector.

A flash or other drive that has an indicator LED is a good idea.