Check your bios. Turn off support for the on board card. Then your pci card should be detected and work. You may also want to try using the alsa cheat code.
I have a motherboard with a built in sound card. The quality isn't great so I put in a Soundblaster card I had lying around. But it doesn't get detected. Is there an incantation from LILO to detect two sound cards?
Ideally what I'd like to do is send system beeps through the onboard sound card and send audio through the soundblaster. Any tips how I could do this?
TIA
Check your bios. Turn off support for the on board card. Then your pci card should be detected and work. You may also want to try using the alsa cheat code.

SK Hynix Server Memory 32GB (1x32GB) RAM DDR4 2400MHz HMA84GR7MFR4N Lot of 12
$1599.99
Major Brand 8 GB PC3L-12800 (DDR3-1600) 2Rx8 DDR3L Laptop Memory RAM
$10.99
Micron MTC4C10163S1UC48BA1 8GB RAM DDR5 4800MHz
$87.00
Samsung 8GB DDR4 2666MHz Desktop Ram Memory (M378A1K43DB2-CTD) Tested
$29.99
Kingston Fury Beast 32GB(2 x 16GB) KF552C36BBEA-16 DDR5 5200MHz RAM - R1031A
$299.95
Corsair CMK32GX4M2B3000C15 Vengeance LPX DDR4 3000mhz Memory Kit - 32GB (2x16GB)
$159.95
SK Hynix 64B PC4-2933Y Server Memory DDR4 RAM HMAA8GR7MJR4N-WM
$499.99
RAMAXEL Lenovo 32GB LPDDR5X CAMM2 7500MHz Laptop RAM | UNTESTED
$445.00
LOT OF 23 Ram Sticks-Corsair Vengeance CMZ8GX3M2A1600C9 4GB (4GBx23=92GB Total)
$129.99
Corsair Vengeance DDR3 8GB 16GB 32GB 1866MHz PC3-14900 Desktop RAM Memory DIMM
$85.00