Jeff Liebermann writes:

On 08 Nov 2009 09:59:16 -0500, (Samuel M.
Goldwasser) wrote:

Diagnostics pass but no sound when doing "Test DirectSound".

Ok, that means you have a working sound chip, but no connection
between the chip and the speaker. I can't tell where it's broken from
here. If you can identify the Realtek sound chip, perhaps you can
find the data sheet and identify the sound output pin. Then, use a
scope to see if it's putting out any sound at the chip. If there's
sound at the chip, but not at the output connector, you have a
motherboard with a possible broken trace, blown audio amp (if
present), or broken coupling cazapitor.

Fonebell Sounds like a busy signal through the PC speaker.

Ooops. I forgot that it default to the timer sound output instead of
the sound output. I wrote that in 1985 and my memory is becoming
rather ummm.... dynamic.

And note that there was no PC speaker installed before. So, there is
a BIOS/POST beep now from the speaker as well.

Some motherboard run the PC speaker audio through the sound card.
Apparently, this one does not. So much for that idea.

But nothing from the speaker in Windoze.

I'll keep looking for some DOS based diagnostics with a sound test. It
may have to wait until I drag myself to my palatial office sometime
next week.

You might find something useful under this review:
http://www.hardwaresecrets.com/article/477 (9 pages)
This might be a diversion but could be causing the sound to be muted:
Viiv support (i.e. support for Quick Resume technology, which
allows the PC to imitate the behavior of TV sets, where by
pressing the power button located on the remote control the
screen goes dark, the sound is muted and the keyboard and
mouse stop responding)"

Bingo. It's a Realtek ALC888 sound chip. Digging...
http://www.realtek.com.tw/products/productsView.aspx?Langid=1&PFid=28&Level=5&Conn=4& ProdID=135
Data sheet link is at the bottom of the page. Section 6.2 shows front
audio outputs on pins 35 and 36. Dust off the oscilloscope and see if
there's any sound on those pins.

Hmmmm. I'm not sure I'm THAT determined to save $7 on an eBay sound
card. Besides, you know what a rats nest it is inside a PC tower
trying to get a scope probe in there!

A broken trace is certainly possible, but wouldn't it have to be at least
two broken traces?

Thanks for all your efforts!

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