Jag suddenly won't output sound

[bigferret]

So...after years of not playing any Jag-related stuff, I've finally got back in the saddle and have been slowly rebuilding my collection. Bought a refurbished Jaguar and have been playing it without issue for about six months until last night. Sound's blasting through the stereo while playing NBA Jam and after about 20 minutes, I pop the cart out and stick T2K in. Only now, when the console boots - there's no sound. When the game plays - no sound. Tried all the usual tricks with in-game sound volume, etc., checked connections....and nothing. Tried other games with the same result. I've looked all over online and can't find a single mention of a Jag losing the ability to play sound so suddenly, so my question is: Could the hardware have failed this abruptly? And would the best way to handle the situation just be to replace the machine?

 

For what it's worth, there was no power spike or anything when I switched carts and video still looks just fine. The Jag's hooked up with a third-party S-Video cable, btw. I also took the Jag apart and can't find any obvious indication of failure (burning smell or board damage.)

 

Any thoughts would be appreciated. This is my fourth Jaguar since 93 and I've never had anything like this happen. I'm really bummed the sound is gone as I just scored a Pro Controller and picked up a copy of of Missile Command 3D that should be arriving soon. Oh well.

[LinkoVitch]

I'd imagine you have tried this, but check the cables, both Jag end and TV end. I had sound disappear on me once, and it was due to the cable partially coming out of the socket on the TV.

 

Other than that, sorry, no ideas.

 

Good luck

[sh3-rg]

I'd imagine you have tried this, but check the cables, both Jag end and TV end. I had sound disappear on me once, and it was due to the cable partially coming out of the socket on the TV.

 

Other than that, sorry, no ideas.

 

Good luck

 

One of my 3rd party scart cables likes to fall away from the jaguar with any passing light breeze and has a really crappy scart connector, that can leave me with no sound or missing colours.

[Zerosquare]

There's a separate voltage regulator that causes loss of sound when it dies, but it's unlikely to fail for no good reason like this. Bad connections somewhere is the most likely culprit.

 

You can use this picture to check the sound signals directly on the motherboard : http://www.atariage.com/forums/index.php?app=core&module=attach&section=attach&attach_rel_module=post&attach_id=149800.

 

 

 

[bigferret]

Thanks for the replies. I have checked cable connections, etc. and thanks to the diagram Zerosquare linked to, I've also closely examined the board and can't find anything. Guess it's time for another Jag........But I'd sure like to know what happened here.

[Zerosquare]

I just thought of something : the power switch in the Jaguar actually has two pair of contacts. One of them switches the power for everything digital and video-related, while the other ones only powers sound-related circuits. So if the power switch is partly defective, you could end up with the symptoms you're getting.

 

Try jiggling the switch a bit to see if there's a bad contact, and cleaning it (use contact cleaner spray if you have some, isopropyl alchohol otherwise). You can also try bypassing the switch completely with wires, and check the voltage on C24 (next to the REG1 chip) with a multimeter to see if the audio section is getting power.

[nonner242]

I just thought of something : the power switch in the Jaguar actually has two pair of contacts. One of them switches the power for everything digital and video-related, while the other ones only powers sound-related circuits. So if the power switch is partly defective, you could end up with the symptoms you're getting.

 

Try jiggling the switch a bit to see if there's a bad contact, and cleaning it (use contact cleaner spray if you have some, isopropyl alchohol otherwise). You can also try bypassing the switch completely with wires, and check the voltage on C24 (next to the REG1 chip) with a multimeter to see if the audio section is getting power.

 

 

Yeah, what Zero said!

[FABombjoy]

There's a separate voltage regulator that causes loss of sound when it dies, but it's unlikely to fail for no good reason like this.

I did have one that was hit or miss due to a lack of solder. It was more or less stuck to the board rather than soldered to it.

 

But echoing the above statements - definitely start at the audio regulator and work backwards or forwards from there.