audio not working

Hello, i have a DELL INSPIRON 1440, windows VISTA sp1, 32-bit operating system.

I usually put my laptop in a hibernate mode instead of shutting it down to save my current activities and save time booting it. Few days ago, i turned my laptop on and audio was still working fine, no problem, and when i restarted it, my audio isn't working anymore. no audio from the speaker nor from the headphone. I didn't install anything and didn't make an update either prior to restarting it.

I did test the speakers, but all i get is this message, "FAILED TO PLAY TEST TONE". I downloaded the driver from dell, uninstalled the driver which is IDT HIGH DEFINITION AUDIO AUDIO CODEC, booted my laptop, install the driver, restarted my laptop, and the audio is still not working.

I tried system restore, but it can't be done. If I restore it to a restore point wherein my audio is still in good working condition, system restore couldn't complete successfully. No changes on my settings. But when I restore it to a point in which my audio isn't working anymore, system restore is successfully completed.

I tried DELL DIAGNOSTICS. From it, I was able to diagnose the problem.
- HEADPHONE PLAYBACK TEST (ERROR CODE:1B63:1A1B)
- INTERNAL MICROPHONE RECORD TEST (ERROR CODE: 1B63:181B)

(fyi: analog sound and internal microphone record test are functioning well.)

what should i do? can DELL FACTORY IMAGE RESTORE (restore factory settings) solve my prob, or is it a hardware issue? your help will be much appreciated. thanks