Cable box optical audio problem (Comcast)

[Executor32]

I have no idea if any of you can help, but I'll post this anyway in case anyone here is a Comcast tech or Motorola engineer or just plain knows how to fix this for whatever reason.

I have a Motorola DCH3200 HD cable box. Lacking a TV, I have it connected to my main monitor's HDMI port, with my PC connected to the DVI port, so I can switch between the two with the button on the side of the monitor if I only want to use one or the other. I also have it connected via the coax cable to my TV tuner card, so I can use my PC and watch TV at the same time by opening WMC on my secondary monitor.

Now, the speakers on my monitor suck and sound all tinny, and my sound card has a TOSLINK input, so I'd like to use that and the TOSLINK output on the cable box to play the sound from the cable box on my PC speakers. Unfortunately, after buying a TOSLINK cable and trying it out, it only works during the weekly EAS test and for 2-3 seconds afterward (until the picture comes back on). During normal watching, the audio is only output over the HDMI cable. I tried accessing the box's settings menu (hit Menu immediately after turning off the box) and changing the HDMI port mode to DVI, but then I get no sound at all. Leaving that alone and setting the audio output mode to passthrough has the same effect. I should note that there is nothing wrong with either the PC or the TOSLINK cable, since I brought my brother's PC in here and connected the TOSLINK cable between his motherboard's output and my sound card's input, and it worked just fine. That, and the fact that it works while the EAS test is going on. I'm sure the fault lies with the cable box.

I've gotten around this problem by running a 3.5mm stereo cable between my sound card's Line In jack and the headphone jack on the monitor, but this is far from ideal because there's always noticeable static, especially when I'm neither watching TV nor playing any audio on the PC. If anyone can help find a proper solution to this problem, I'd really appreciate it.

[Executor32]

I forgot to mention, if I look in the diagnostics menu, under Interface/Port Status the SP/DIF connection is both enabled and active, and under Audio/Video Status the output mode for the SP/DIF connection is Dolby Digital 3/2 with 1 LFE channel. So, it knows it's connected, it just doesn't want to output through it except during the weekly EAS test.

[Dominus Atheos]

Call comcast and tell them you have a normal tv and receiver, then explain the problem to them.

[Executor32]

Last time I called Comcast for something (activating this box since the over-the-Internet activation wasn't working), I got some chick in India or something who had no idea what I was talking about. Three hours later, and an hour after being directed to the Comcast support live chat, I finally got it activated and working. You can see why I'd prefer to avoid Comcast's official support channels.

[Dalton]

Haha, I decided to try to Google your problem and found your support post on Comcast's site. Anyway, I'm becoming more and more suspicious that you may be running into some form of DRM shenanigans; if the box detects that it's plugged directly into a computer, it may assume you are trying to record the output. Maybe. Call me nuts. Perhaps run it through a receiver and see what happens.

[Executor32]

As far as I know, S/PDIF doesn't have any sort of DRM, unlike HDMI. If there were to be any DRM isues with my setup, I would think it'd be with the HDMI connection to the monitor. It's HDCP-compliant, though, and save for the sound quality on the terrible built-in speakers, it works perfectly. I'm starting to think it's just a shortcoming of this model of cable box.