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No sound output from Compaq Ultra-sound 32

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First post, by jesolo

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I recently managed to get hold of a Compaq Ultra-sound 32 sound card.
Card arrived and I instaled it in my 486 class PC (Asus PVI-486SP3 with a Pentium Overdrive P24T CPU currently plugged in).
Upon booting up, the Plug 'n Play BIOS immediately recognises the card.
I booted into Windows 95, it also recognised the card, after which I installed the sound card drivers.

I played a bit around with the card, trying out a couple of demos and it worked fine.
Over the weekend I played around a bit with the sound card settings and then shut the PC down.
When I booted up the PC tonight, suddenly no sound output coming from the sound card (both the Line out & Speaker Out).
The BIOS still recognises the card, it still initliases itself via the Interwave utilties in the Autoexec.bat file, but just no sound output, completely silent.

I'm looking for perhaps any ideas in helping me to resolve my problem. What could be wrong that there is no sound output?
Here's a link to a page with a pic of the card (second pic):

EC251 InterWave Audio Card

Reply 1 of 3, by jesolo

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Update: Upon closer inspection, it would appear that some pressure was applied on some components of the card during shipping.
It would appear that the transistor in the lower left corner of the card (refer pic in previous post), just above C147 and the 16-bit part of the connectors, has completely been loosened and actually now came off after I inspected it more closely.
It has markings on it of S 2N 3904 (I've typed it as it is printed on the transistor). From what I can see, is a fairly common small-signal transistor.

Not that I know much about electronics, but can this particular transistor lead to no sound output being generated from either the line out and the speaker out?

Reply 2 of 3, by Jepael

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jesolo wrote:
Update: Upon closer inspection, it would appear that some pressure was applied on some components of the card during shipping. […]
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Update: Upon closer inspection, it would appear that some pressure was applied on some components of the card during shipping.
It would appear that the transistor in the lower left corner of the card (refer pic in previous post), just above C147 and the 16-bit part of the connectors, has completely been loosened and actually now came off after I inspected it more closely.
It has markings on it of S 2N 3904 (I've typed it as it is printed on the transistor). From what I can see, is a fairly common small-signal transistor.

Not that I know much about electronics, but can this particular transistor lead to no sound output being generated from either the line out and the speaker out?

Most likely square pin is ground because it is emitter of the NPN transistor, and it looks like base is driven trough 20kohm resistor R80, and it also looks like the collector is pulled to some supply voltage through another 20kohm resistor R85. But otherwise it's impossible to say what it does because who knows where the PCB traces go. It appears to just invert a signal. So of course it can be the cause of no sound. Just solder it back on and try again.

Reply 3 of 3, by jesolo

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Thanks for the input.
Unfortunately, the transistor broke off from just underside the base.
I will have to desolder the three pins sticking out of the board and replace it with a new transistor.
Hopefully, I won't have too much trouble desoldering the three pins and soldering a new transistor back on.

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