Logitech Z-2300 Speaker System no longer working

Aloha,
My external speakers are no long working. Identified above and controlled by Realtek HD Audio Manager. They are connected to the default line in jack on my Gigabyte mobo GA-MA78GM-US2H. This is a fused speaker system and the fuse is good. A check in Device Manager shows the sound, video, and game controllers to have current drivers and functioning. The speakers system is plugged in and power is on. I have tried other speakers and they don't work either.
Is this a WIN7(x64)software or Hardware problem?
Mahalo-n-aloha...konadon

Aloha fireberd,
Thank you for taking the time to reply...Yes, thank you for the correction...they're plugged into the green default line out jack. I've checked again within the "HD Audio Manager" to make sure I hadn't reconfigured the green jack and its assignment is correct.
All is not lost, I've connected a "Front Panel Audio Module" into the mobo "front panel audio header" and then configured it so that it does not mute the rear speakers, in case devine intervention corrects the problem.
I'm beginning to believe that the mobo integrated sound panel is dead. But I have not yet hooked the z2300 system to another computer, so it could also be the speaker system crashed.
anyway...thx for your interest.
mahalo-n-aloha...konadon

aloha all,
It's occurred to me that I haven't given my system specs, sorry
OPERATING SYSTEM
WIN7 x64 SP1 (build 7061)
PROCESSOR
2.30 gigahertz AMD Phenom 9650 Quad-Core
256 kilobyte primary memory cache
512 kilobyte secondary memory cache
64-bit ready, Multi-core (4 total) Not hyper-threaded
MOBO
GIGABYTE GA-MA78GM-US2H
BUS CLOCK 200 MHz
BIOS: F2 01/02/2009
DRIVES
ATAPI iHBS112 2 SCSI CdRom Device [Optical drive]
TSSTcorp CDDVDW SH-224BB SCSI CdRom Device [Optical drive]
Corsair Force 3 SSD [Hard drive] (60.02 GB)
ST31000528AS [Hard drive] (1000.20 GB)
ST3200827AS [Hard drive] (200.05 GB)
ST3250310AS [Hard drive] (250.06 GB)
ST3500630AS [Hard drive] (500.11 GB)
VIDEO CARD
AMD RADEON HD6750 #H675FS1G
SOUND (onboard)
AMD High Definition Audio Device
Realtek High Definition Audio

Problem update...I've connected the spkr system to another machine and it works fine. I then reconnected to this machine and it only works when plugged into the "Front Panel Audio Module".
The last time the spkrs were working was when the system OS was WinXPPROSP3. I upgraded to WIN7 about 6 months ago but didn't hook up the spkrs. So, I'm narrowing the problem down to either bad drivers or dead mobo onboard sound module.
I've done the sound card properties driver update for both and the message returned reflects current driver for both, however that might not be very trustworthy. I've tried to ID the Vendor for each of the onboard sound systems but cant find a URL that will give me the vendor name from my hardware Id code. The codes are
AMD.....HDAUDIO\FUNC_01&VEN_1002&DEV_AA01&SUBSYS_00AA0100&REV_100
HDAUDIO\FUNC_01&VEN_1002&DEV_AA01&SUBSYS_00AA0100
REALTEK.....HDAUDIO\FUNC_01&VEN_10EC&DEV_0885&SUBSYS_1458A002&REV_100
HDAUDIO\FUNC_01&VEN_10EC&DEV_0885&SUBSYS_1458A002

Can anyone tell me who the vendor and device name is or refer me to a URL that'll interpret my info,
Mahalo-n-aloha.....konadon