No Sound?

About original Memotech hardware.
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AndyGarton
Posts: 29
Joined: 27 Jun 2013 10:46

No Sound?

Post by AndyGarton »

Struggling (ok, massive failure) to get any audio from my MTX - I've tried both an RF lead, and a cobbled together collection of converters and leads (if somebody could provide a link to a supplier of the exact cable I need without this mess then I'd appreciate it) from the "Hi Fi" socket, without joy. Any ideas please? Although my RF picture is terrible (a dodgy modulator wotsit I assume), it's not so bad that sound wouldn't work, so I assume I do actually have a hardware issue. I wouldn't be surprised if the "Hi Fi" lead is bad, but the fact that RF audio isn't working is bad, surely.

(I'm assuming also that the "Toado" game does produce sound as you play, because this is my main test case!)
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Dave
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Re: No Sound?

Post by Dave »

Hi Andy,

you're not having much luck are you!

I wouldn't dare to suggest that you check for the TV being "muted", or the volume being turned down too low :-)

For the Hi-Fi output, the connector on the rear panel is worth looking at, there is a grey cable that connects to the output of the video board and it is very fragile / easily broken.

As you say, that will not affect the modulator sound though, yes, Toado produces sound. It is possible that the modulator audio frequency is off. To eliminate that possibility, I would work with the Hi-Fi output first.

As a basic test, you can do <CTRL><G> just from BASIC and you should hear a "Ding".

There are some sound faults described in the Service manual - one possible cause is a failed sound chip (obviously).

regards
Dave
AndyGarton
Posts: 29
Joined: 27 Jun 2013 10:46

Re: No Sound?

Post by AndyGarton »

Thanks Dave, I'll try those things asap.
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Dave
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Re: No Sound?

Post by Dave »

Hi Andy,

I maybe didn't say enough on your first point, the "Hi-Fi" lead to your TV is nothing special - just a phono to phono lead, like any of the ones you will have seen on an old style hi-fi seperate - you know, the Red and White split lead cables. If you use one channel, you'll only get sound on one channel obviously, but if there is no hardware fault, it will work.

So, you just need to put a BNC to phono adapter on the MTX Video output and you can use the other half of your Red/White phono cable (or a yellow plugged cable) to connect to your TV Composite Video input with the sound to the audio input

regards
Dave
AndyGarton
Posts: 29
Joined: 27 Jun 2013 10:46

Re: No Sound

Post by AndyGarton »

Just to "close the loop" on this one - the audio out socket wasn't actually connected to the internal cable at all (oddly the audio part of the cable had been taped back to the rest of the cable, seemingly deliberately avoiding the correct connection). Soldering it back on restored my audio - thanks again to Dave for the clue!
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1024MAK
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Joined: 24 Dec 2012 03:01
Location: Looking forward to summer, in Somerset, UK

Re: No Sound

Post by 1024MAK »

AndyGarton wrote:Just to "close the loop" on this one - the audio out socket wasn't actually connected to the internal cable at all (oddly the audio part of the cable had been taped back to the rest of the cable, seemingly deliberately avoiding the correct connection). Soldering it back on restored my audio - thanks again to Dave for the clue!
Them pesky wires to the audio and video sockets do have a nasty habit of becoming loose and "free" :evil:
I had to solder two connections back on at Memofest...

Maybe a previous owner used UHF, so when the wire broke free, they just taped it up.

Glad to hear that you fixed it, and even better, updated all us nosy MTXers :mrgreen:

Mark
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