I assume the sound output of your tv card goes through line in. Try KMix to deselect line in.
I love the new Knoppix DVD but have a problem I haven't encountered with any other distro of Linux - previous Knoppix included:
I have an old ATI TV Card in my computer and when my machine boots with Knoppix, it "senses" the card and immediate begins playing TV sound. If I try to load the TV software xawtv, the software works flawlessly - as good as the MS software that was made for the card. However, if I close the program, the sound stays on until I turn off the machine.
Of course I could mute it, but finding out how to fix the problem is so much more fun.
I assume the sound output of your tv card goes through line in. Try KMix to deselect line in.
ASRock Z170M-ITX/ac LGA 1151 Intel Z170 HDMI USB 3.0 Mini ITX Intel Motherboard
$49.99
ASRock B550M Pro SE AM4 DDR4 SATA 6Gb/s 1 PCIe 4.0 x16 Micro ATX Motherboard
$84.99
MSI H81M-P33 Desktop Motherboard Intel MicroATX Socket LGA1150 USB 3.0 W/IO
$26.99
Gigabyte GA-Q170M-D3H-GSM LGA1151 DDR4 Desktop Motherboard with I/O Plate
$49.99
Asus Prime H310M-A R2.0 Intel LGA 1151 DDR4 Desktop Motherboard
$54.99
Asus H81M-C Intel LGA1150 DDR3 Desktop Motherboard MicroATX Socket H3
$23.99
Gigabyte Z370P D3 ATX Z370 LGA1151 Motherboard (Support Intel 6/7th 8th 9th)
$59.99
ASUS H87I-PLUS, LGA 1150, Intel Motherboard w/ IO Shield
$39.00
MSI PRO B650-P WiFi AMD AM5 DDR5 WiFi 6E ProSeries Motherboard
$107.30
Asus Prime H310M-A R2.0 Intel LGA 1151 DDR4 Motherboard w/ I/O Shield
$59.99