no sound on ibm thinkcentre m52 8212-1yu

Hi! I just got one of base IBM ThinkCentre M52 computers (8212-1yU).

Thanks in advance for your time and help!

This computer has windows 7 (32-bit) and Intel Pentium 4 CPU 3.00 GHz.

Under Device Manager, I see the following entries under "Sound, video and game controllers":

• High definition audio device

When I go to Control Panel --> Sounds and Audio Devices, it says "No Audio Device"."speakers not plugged in" the default device is the digital audio which is working but no sound out of the inside speaker

the sound card is built in on the motherboard, I checked Lenovo support site

There is no sound on this PC, though there are outlets for mic and speakers. I tried hooking up my headset, but here is no sound.

Micrsoft's Mr. Fixit utility

Any help would be greatly appreciated!