I recently won an eBay auction for a Sound Blaster 16 CT2291 ('Pro Value'?) It's a non-PNP card with an IDE interface (which cannot be disabled) and a real Yamaha OPL chip. The PBC is labelled CT2910.

All of the jumpers are set to their defaults (IRQ 5 / 220 / 330 / DMA 1&5).

I have tested the card in my P133 430HX board under Windows 95, 98SE and NT4, and on my 386SX40 under a fresh installation of MSDOS6.22 with just the 'SBBASIC' creative drivers loaded. I have cleaned the contacts on the ISA card and tried multiple ISA slots in the Pentium system. The only other expansion card in the Pentium is the graphics card, and the motherboard has no onboard audio. In all cases the symptoms are the same:

- The IDE interface works in Win95 (or at least I got it working once)
- 8 and 16-bit audio (e.g. WAV files) is absolutely fine
- FM synthesis (Midi files in Windows, test music in DIAGNOSE.EXE for DOS) consistently fails to work. Either I get silence or massively distorted output that is almost unrecognisable as music.

In addition when you first turn the computer on there is a lot of interference through the speakers (which increases at times of heavy disk access) but this dies down after a time. In Windows it can be eliminated by turning down the MIDI volume in the Mixer.

I conclude that my eBay purchase is a bit broken. It arrived wrapped in bubble wrap - no anti static bag 🙁 Thankfully it wasn't too expensive.

Visibly there's nothing obviously wrong with the card. I'd suspect the caps, but not sure which ones are specific to the FM side of the card? Does anyone have any helpful suggestions, or should I just give in and buy an Audician 32 / a newer CT4170 / something else?