[mythtv-users] PVR 350/500 problems (garbage in video, pulsating audio)

Ronald Frazier ron at ronfrazier.net
Thu May 1 12:21:13 UTC 2008

>     I have had the first problem on my PVR-250 before, It was due to the
>  encoder chip overheating.

I suppose that could make a lot of sense. Those encoder chips do get
pretty hot.  In my old case, I had them several slots apart, and never
once had this problem in the 2+ years it was running. But my new
motherboard only has 2 adjacent PCI slots, so they are back to back.
Since the 350 only has 1 encoder (vs 2 on the 500) I figured that
would be the better one to put in the upper PCI slot. Makes sense why
it would be the one to suddenly start having problems.

My case actually has pretty good cooling. Its in the basement, where
ambient temperature is low. Its a core 2 duo, so it doesn't get that
hot to begin with (sometimes the CPU fan even shuts itself off when
idle). Its got a duct venting the CPU fan straight out the side of the
case, plus a 120mm powersupply fan and another 120mm fan on back. Yet,
in spite of all of that, I could see how airflow between 2 adjacent
cards could be substandard.  The question now is how to rig it to get
better airflow between the cards. Theres no place to attach a fan for
blowing direction on the cards. I'll have to see if someone makes an
L-bracket to attach one to the bottom of a tower case (or, if
necessary, fabricate one).

>  I havn't heard that audio problem before. What are you recording from
>  the tuner or line-in?
>  If your analog line cables are poor quality, it could cause all kinds of
>  wierd problems.

I'm using the tuner. The audio quality on the 350 is just fine, so if
thats the problem it's either the splitter itself or the 6" cable
leading from the splitter to the 500. I'll try removing the cable
before the splitter and connecting directly to the 500.

Now that I think about it, I haven't watched that much analog in the
last few months. I only noticed the problem about 3 weeks ago, and I
did do some rewiring in the server's cubby hole about 5-6 weeks ago.
That seems like suspicious timing, and is very likely the cause. I
don't know why it didn't occur to me before.

Thanks for the suggestions. I'll give it a try.


More information about the mythtv-users mailing list