A search does not turn up anything concrete for these speakers. Do you have the actual Dell model number rather than the part number. This is mostly a users helping users forum, with a Dell moderator.
In general, check all cabling, reseat the connection to the PC (unplug then plug back in). Plug the speakers into the front headphone jack and see if you get audio. Finally, may be a PC issue, check the audio playback device, it should be set to "Speakers". Also, plug a headphone into the rear GREEN speaker jack and see if you have audio, that will determine if its the PC or the Speakers.
Dell forum member since 2002
Dell Inspiron 15 - 5577 Laptop
Home Built Desktop PC with ASUS ROG Z170, i7 6700K CPU
Windows 10 64 bit Pro and Windows 10 Insider Program Beta Versions. SSD drives. Cakewalk by BandLab and Studio One 4.1 Recordng Studio Software.
Dell S2719dgf Monitor
Member of Nashville based R.O.P.E.
I would try re-seating all plugs.
Yes, PC speaker and Subs sets can malfunction. I've fixed a couple in my days.
However, before I wrote-it-off ... I would test with some other know-good machines or devices.