iMac G3 400 that is sound-less...

Hey folks, I just bought my first Mac the other day: a used (but well taken care of) iMac G3 400. The system has only one issue: NO SOUND!

It's got a 9GB HD, about 512M RAM, and I just installed OS 10.3 . Everything is smooth as silk except that the sound doesn't work at all from the headphone jacks, from the internal speakers, or from external speakers. I'm at a loss as to what may be causing it.

Here's what I've checked so far:
I opened 'er up and examined the speaker connections to no avail.
I have tried the volume numerous times to no avail.
I have tried headphones in both of the front headphone ports, to no avail.
I checked the sound in the (Control panel?... I know that's a Windows term) and it listed headphones, but no internal sound.

I'm out of ideas, can anyone help?

I still think I got a pretty good deal for $50 with a printer, even if I can't use the internal DVD drive to play movies with sound. AMIRITE?

Our last machine was the iMac G3 400 DV model. It went through 2 earphone jacks, many thanks to our kids. If you check under Sound I believe, it will tell you what it thinks is connected/engaged. The earphone board was easy to change though you had to strip many layers down to get to it.

That is my guess. Been there and done that. We went soundless for about a year till other issues come up and we retired it after 8 years of service.